Color regulating device for illumination and apparatus using the same, and method of regulating color

ABSTRACT

There is provided a color regulating device for illumination. The color regulating device includes a light-valving structure for adjusting a flux ratio of outgoing light through the light-valving structure to incident light entering the light-valving structure, and a color-adjusting structure having a wavelength-band converting element for changing incident light with a wavelength band into outgoing light with a different wavelength band through the element. Wherein, the light-valving structure and the color-adjusting structure at least partially overlap on the traveling path of light, forming at least one overlapping structure. Mixing the outgoing lights of the light source passing through light-valving structure, the color-adjusting structure, and the overlapping structure to obtain a different wavelength band (or color temperature) from that of the light source. 
     There are also provided a color adjusting apparatus for illumination including the color adjusting device and a color adjusting method.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.13/668,738, filed Nov. 5, 2012, which claims priority to U.S.provisional application Ser. No. 61/559,373, filed Nov. 14, 2011. Theentire disclosures of all the above application are hereby incorporatedby reference herein.

BACKGROUND

1. Technical Field

The present invention is related to a color regulating device forillumination, a color regulating apparatus for illumination using thecolor regulating device, and a color regulating method.

2. Description of Related Art

Human life style has greatly changed since Edison invented incandescentlamps, and more durable, aesthetic and efficient illumination productshave been advanced and developed continuously.

However, because sunlight has been adapted during the human evolution,human visual organs still favors natural illumination environment evenwhen situated under artificial illumination. Sense of structures ofhuman eyes to visible light changes based on variation of lightwavelength and brightness of the environment. When visible light affectson human eyes to generate light sense, it is not only related to thecomposition and intensity of light, but also related to physiologicalcharacteristics of human visual organs and psychological factors ofhuman. Therefore, it is necessary to evaluate visual effect generated bylight radiation according to physiological characteristics of human eyesand agreed regulations through “light measurement.”

Because light measurement relies on physiological characteristics ofhuman visual organs, the Commission Internationale de l'Eclariage (CIE)unifies and sets the evaluation standard of the light sensing capabilityof human eye. Human eye sensitivity function V(λ) has been set forth toconnect and convert the radiation measurement and light measurement, andchromaticity diagrams are used to standardize to human eye sense ofcolor. In 1924, CIE set forth that in an equal energy spectrumexperiment of a small field of view of 2 degree, eye sensitivityfunction of a point light source under a photopic vision condition iscalled CIE 1931 eye sensitivity function and is relied to derive a CIE1931 color space chromaticity diagram, as shown in FIG. 1. Because humaneye has different light vision performance under different wavelengths,CIE, according to the human eye sensitivity to blue and indigo spectrumzones, sets forth CIE 1978 eye sensitivity function in 1978. Thiscorrected function has higher responded value in the spectrum zone withwavelength being lower than 460 nm. However, although the CIE 1978 eyesensitivity function is the most accurate sensitivity description, theCIE 1391 is the most used color space chromaticity diagram in the worldat present.

White light is the most widely used light source in the application ofillumination. Because of the characteristics of the light metamerism,many spectrum combinations can be found from the chromaticity diagram toform white light. Because the characteristic difference amount all whitelights is “color temperature,” the color temperature relative to thechromaticity coordinate becomes an importance parameter of describingthe characteristic of white light source. “Color temperature” is theparameter of “absolute temperature of the surface of a black body” torepresent a spectrum distribution of a light source when such spectrumdistribution is the same of a spectrum radiated from the black body.(The black body means an object that absorbs the radiation of anywavelength falling downward to its surface at any temperature.) Insummary, color temperature is an expressing manner defined according tolight color variation emitted from black body radiation, and theexpressing manner of the defined color employs the unit of absolutetemperature Kelvin (K). When the black body is heated, the outer surfaceof the black body under different temperatures emits different coloredlight. For example, when heated to 1000K, the black body presents red,red-yellow is presented below 3000K, white is presented from about 3000Kto 6500K, and white light turns a little blue over 6500K. Because “colortemperature” can be simply used to describe a specific spectrum, it isused to be a standard in the illumination field.

According to temperature variation, the color temperature of the lightemitted from the black body can be used to depict a locus in thechromaticity diagram. The locus of the black body radiation spectrum inthe CIE 1931 color space chromaticity diagram is called “PlanckianLocus” or Black Body Locus (BBL). The white light spectrum in thenatural world is greatly similar to the Planckian spectrum. The locusaa′ in FIG. 1 indicates the “black body locus” of the Planckian blackbody radiation spectrum in the CIE 1931 color space chromaticity diagramand the corresponding color of its color temperature.

In the aspect of color temperature control, for a white lightilluminating lamp, different color temperatures have differentapplication fields. For example, the color temperature below 3,300 K iscalled “warm light,” which is close to the incandescent lamp, has morered composition and provides people with feelings of warmth, health andcomfort. Therefore, warn color light is adapted suitably to families,residences, dormitories, guest houses or places with low temperatures,etc. The color temperature from 3,300 K to 5,300 K is called “cold whitelight.” Because such light is soft, it makes people feel joyful,comfortable and peaceful. Such cold light is adapted suitably to stores,hospitals, offices, restaurants and waiting rooms, etc. Colortemperature over the absolute temperature 5,300 K is called “coldlight,” which is most close to natural light, and is bright to makepeople concentrate. Such cold light is adapted suitably to offices,conference rooms, classrooms, drafting rooms, design rooms, readingrooms of libraries and display cabinets, etc. Therefore, a good whitelight illuminating device necessarily completes adjustment of colortemperature to greatly increase its application and value.

Furthermore, to evaluate whether the white light source is close tonatural light, “color rendering index” of an object under illuminationalso becomes an important parameter. The object under illumination ofsunlight or an incandescent lamp shows so-called “true color” becausethe characteristics of broadband of such light sources. The level of thetrue color presented from the object by the light source is called“color rendering index (CRI or Ra)” to evaluate the color rendering ofthe light source. A standard light source is used as a reference value,and Ra thereof is 100; the rest of the light sources have Ra lower than100. When Ra value is larger, the color rendering of the light source isbetter. The Ra of the incandescent lamp can reach to 98. Because humaneyes evolve to adapt to daylight environment, CIE employs the black bodyradiation spectrum of Planckian locus as an evaluation basis. Todaylight of every time phase falling into an extent at a little distanceto the Planckian locus, the color rendering ratio is very high.

In the modern illumination apparatuses, the most common light sourcesinclude halogen lamps, fluorescent lamp, cold cathode fluorescent lamp(CCFL), and light emitting diodes (LEDs), etc. Once an illuminatinglight source is completely manufactured, both color temperature andcolor rendering thereof are not adjusted easily anymore. With regard toconventional illumination apparatuses, common incandescent tungstenlamps have good color rendering but short lifespan and low luminousefficiency. Halogen lamps have improved lifespan and luminous efficiencywhen compared with incandescent lamps but high heat and ultravioletthereof are criticized. Furthermore, conventional illumination devicesbased on principles of operation of incandescent lamps are all limitedby overheating and unchangeableness of color temperature and colorrendering after leaving factories. With regard to CCFL, it is noteco-friendly because of contained mercury and also has problems ofinsufficient color rendering. Recently, LED comparatively has advantagesof compact volume, excellent light emitting efficiency, long lifespanand quick operating reaction time and complies environmental protectionrequirements of non-radiation and non-poisonous material such mercury sothat having superiority when compared with other conventionalilluminating light sources.

An LED is fabricated by using semiconductor process technologies torealize an optical element based on semiconductor diodes, it convertselectricity to light wave, radiation spectrum belongs to mono colorlight and wavelength includes infrared, visible light and ultraviolet.Because the LED is required to form illuminative white light, thewavelength spectrum needs to cross red, green and blue wavelength bandsof three primary colors of light to further mix into light beam. Inother words, the wavelength needs to cross 300 nm (from about 400 nm to700 nm). However, because the energy difference of a full-width athalf-maximum of the radiation spectrum of the LED is very narrow, it canonly emit mono light with a mono wavelength. Since a long time ago, LEDis limited by the slow development of blue light wavelength band ofthree primary colors, because the brightness of the emitted blue lightwas not good and thus it cannot achieve true color images and whitelight illumination.

To realize white light illumination of LED, methods used by businessesare classified into two types. The first method is to combine LED chipsthat emit different wavelengths. For example, combination of red, greenand blue LEDs or combination of blue and yellow-green LEDs is used.Electric current regulating each LED is controlled separately and alight diffusing film layer is then applied to emitted LEDs to mix andform white light. The other method is to employ material capable ofconverting wavelength, such as a semiconductor, phosphor or dye tocooperate with a mono light LED to achieve the purpose of emitting whitelight. The matured one of such white light emitting technologies is thetechnology that uses phosphor to cooperate with mono light LED. In 1996,Nichia Chemical Industries, Ltd. of Japan developed to use blue(Ga_(x)In_(1-x)N) LED to cooperate with yttrium aluminum garnet (YAG)phosphor emitting out yellow light to form a white light source. Yellowphosphor absorbs part of blue light emitted by the blue LED and thenradiates out yellow light with longer wavelength. Finally, the lights ofdifferent colors are mixed into white light. Such method only needs onegroup of LED chips of the same color. Another common phosphor is terbiumaluminum garnet (TAG) phosphor, which has worse light emittingefficiency but exhibits better color rendering when compared with YAG.The present method, cooperating the wavelength converting materialcapable of converting wavelength of the mono color LED to achieve whitelight illumination, still cooperates blue LED with yellow YAG or TAGphosphor.

However, newly risen LED light sources still cannot replace conventionalillumination apparatuses. The major cause is that all marketable LEDlamp products lack the characteristic presenting a uniform colortemperature so that difference of color temperature between products isinevitable. The marketable white light LEDs mostly use blue LEDs andyellow phosphor to mix color. The present blue light LED manufacturingprocess has gradually become mature. However, when the blue light LEDcooperates with the yellow fluorescent light to mix and form whitelight, a bias away from a predetermined zone of color temperaturehappens due to the mixing of luminous flux generated from the blue lightand yellow phosphor has great uncertainty so that the factory colortemperature of each product cannot be controlled accurately. The causesof uncertainty include phosphor mixing ratio during manufacture,uniformity of phosphor distribution, time control of phosphor dispensingduring mass production and corresponding LEDs which may have differentcharacteristics. The present mass production of white light source bycooperating phosphor with LEDs still causes an inaccuracy of more thanpositive and negative 200K. However, human eyes can sense and feel thecolor temperature variation of a light source once the color temperaturevariation is more than positive and negative 100K. A more sensitiveperson can even become aware of color temperature difference down to50K. Therefore, general illumination products have a tolerance reducedfrom 100K to 50K at present. White light LEDs are limited by manyabove-mentioned factors of uncertainty and the yield thereof is greatlydecreased. Defective samples have no choice but sell by lowered prices.

FIG. 2 is a diagram of CIE 1931 chromaticity coordinate and colortolerance, which sets up specifications for the chromaticity of solidstate lighting products for electric lamps of ANSI C78.377A of whitelight LEDs under different color temperatures. The intervening curveshown in FIG. 2 is part of the curvature aa′, a black body locus (BBL)in FIG. 1. The edge of each small grid along the up and down directionof BBL in FIG. 2 is about 50K, which represents that chromaticity withinthe grid is deemed “the same color temperature” because human eyescannot distinguish any difference from color temperatures within thesame grid. A common white light source for illumination has its colortemperature at least inside a certain zone of the figure. Therefore, fora present indoor light source assembled from multiple LED chips, onceany of the LED chips is damaged, all of the LED chips will need to bereplaced completely to achieve the uniformity of color temperatures ofall light sources.

As mentioned above, most of marketable white light LEDs use blue lightLED and yellow phosphor to mix colors and the disadvantage thereof isthat the factory color temperature of each product cannot be controlled.The reason for failure in accurate control is that the mixing ofluminous flux of from the blue light and yellow phosphor has greatuncertainty. Furthermore, a specific color temperature of each batch ofwhite light sources is completed by mixing out a specific ratio ofphosphor and the ratio cannot be changed by itself after package. Suchmethod cannot arbitrarily adjust and change color temperature of thewhite light source so the applicability and value of the illuminationapparatuses are greatly lowered. Moreover, the light source for indoorillumination should meet the criteria of suitable brightness, cozy lightfield, and color consistency between space and time. However, many LEDlight sources in the market have the issue of the space color shift,which refers to a “yellow halo” resulting from a blue shift in themiddle and yellow shift in periphery. The space color shift may renderadverse effect to the human body in the case of extremely high colortemperature at certain angles.

In addition, at present three colors of red, blue and green LED lightsource are also used. With controlling the relative intensity bycircuit, a white LED light can be made. However, in that three colorshave different decay rates (in which red LED is the fast one), asignificant color shift occurs after using for a period of time. Thepresent various light sources for illumination apparatuses or adjustmentof wavelength, including LEDs, have serious problems on or cannotcompletely control the variation and adjustment of color temperature andcolor rendering. To increase the quality of light sources and theapplication value of products (for example, illumination), the presentlight source devices such as for illumination have great difficulty toovercome. Therefore, a method how to accurately adjust the spectrumdistribution or wavelength band of final outgoing light is greatlyvaluable in applications of illumination and may be used in the otherapplication fields that highly require the quality of light sources.

SUMMARY

One embodiment of the present invention is to provide a color regulatingdevice for lighting, configured to regulate a color temperature of lightinteracting with the device, comprising a light-valving structure foradjusting a flux ratio of a first incident light to a first outgoinglight of the light interacted with the light-valving structure; and acolor-adjusting structure having at least one wavelength-band convertingelement, configured to convert a second incident light with a firstwavelength band into a second outgoing light with a second wavelengthband, wherein the light-valving structure and the color-adjustingstructure at least partially overlap on a traveling path of the light,forming at least one overlapping structure, such that at least a portionof the light becomes a third outgoing light, and the first outgoinglight, the second outgoing light and the third outgoing light are mixedto form a hybrid light with a color temperature different from that ofthe light.

According to another embodiment of the present invention, the positionof the light-valving structure is in front of the color-adjustingstructure, wherein at least part of the first outgoing light through thelight-valving structure enters the color-adjusting structure.

According to the other embodiment of the present invention, the positionof the light-valving structure is behind the color-adjusting structure,wherein at least part of the second outgoing light through thecolor-adjusting structure enters the light-valving structure.

An embodiment of the present invention is to provide an illuminationapparatus comprising: a light source and the aforementioned colorregulating device for lighting.

An embodiment of the present invention is to provide a color regulatingmethod comprising: providing a first light source for emitting a firstlight; providing a light-valving structure and adjusting a flux ratio ofa first incident light to a first outgoing light of the first lightinteracted with the light-valving structure; providing a color-adjustingstructure having at least one wavelength-band converting element andconverting a second incident light with a first wavelength band into asecond outgoing light with a second wavelength band, wherein thelight-valving structure and the color-adjusting structure at leastpartially overlap on a traveling path of the first light, forming atleast one overlapping structure, such that at least a portion of thefirst light becomes a third outgoing light; and mixing the firstoutgoing light, the second outgoing light and the third outgoing lightto form a hybrid light with a color temperature different from that ofthe first light.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned and other objects, features, and advantages of thepresent invention will be more readily understood following a review ofthe attached drawings and the accompanying specification and claims.

FIG. 1 shows a CIE 1931 color space chromaticity diagram containingPlanckian black body locus and embodiments of regulating thechromaticity coordinate and color temperature according to the presentinvention.

FIG. 2 is a diagram of CIE 1931 chromaticity coordinate and colortolerance, which sets up specifications for the chromaticity of solidstate lighting products for electric lamps of ANSI C78.377A of whitelight LEDs under different color temperatures.

FIG. 3 shows a schematic diagram of a color regulating device forillumination according to an embodiment of the present invention.

FIG. 4 shows a schematic diagram of a color regulating device forillumination according to another embodiment of the present invention.

FIG. 5 shows a schematic diagram of a color regulating device forillumination according to another embodiment of the present invention.

FIG. 6 shows a schematic diagram of a color regulating device forillumination according to another embodiment of the present invention.

FIG. 7 shows a schematic diagram of a liquid crystal layer structure.

FIGS. 8A and 8B respectively show a diagram of a basic framework of a90° twisted nematic (TN) type liquid crystal cell under NW and NB modes.

FIG. 9 shows a curve of light transmission through the liquid crystalcell versus applied voltage.

FIG. 10 shows a color regulating device for illumination according to anembodiment of the present invention.

FIGS. 11A and 11B are cross sectional schematic views along line DD′according to FIG. 10.

FIG. 12 is a CIE 1931 chromaticity diagram and chromaticity coordinatesand adjustment of color temperatures of embodiments according to thepresent invention.

FIG. 13 is a CIE 1931 chromaticity diagram and chromaticity coordinatesand adjustment of color temperatures of embodiments according to thepresent invention.

FIGS. 14A-F are schematic views of patterns of phosphor distribution.

FIG. 15 shows an embodiment of the color regulating device forillumination in according to the present invention.

FIG. 16 shows an embodiment of the color regulating device forillumination in according to the present invention.

FIG. 17 shows an embodiment of the color regulating device forillumination in according to the present invention.

FIG. 18 shows a schematic diagram of an interference structure elementmade of the MEMS according to an embodiment of the present invention.

FIGS. 19A and 19B show an embodiment of the color regulating device forillumination in according to the present invention.

FIGS. 20A and 20B show a color regulating device for illumination of anembodiment in according to the present invention.

FIG. 21 is a CIE 1931 chromaticity diagram and chromaticity coordinatesand adjustment of color temperatures of embodiments according to thepresent invention.

FIG. 22 is a CIE 1931 chromaticity diagram and chromaticity coordinatesand adjustment of color temperatures of embodiments according to thepresent invention.

FIG. 23 shows a color regulating device for illumination of anembodiment in according to the present invention.

FIG. 24 is a CIE 1931 chromaticity diagram and chromaticity coordinatesand adjustment of color temperatures of embodiments according to thepresent invention.

FIGS. 25A and 25B show color regulating apparatuses for illuminationaccording to the present invention.

FIGS. 26A and 26B show color regulating apparatuses for illuminationaccording to the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

In the following paragraphs, multiple exemplary embodiments will bedescribed in detail with reference to attached drawings. However, for aperson of ordinary skill in the art, changes or modifications may bemade without departing from the scope of the present invention. However,exemplary embodiments of the present invention will be provided to makea person of ordinary skill in the art to understand the disclosedcontents of the present invention more explicitly. It is noteworthy thatthe present invention may be embodied by many different manners so thatthe exemplary embodiments should not be explained to limit the presentinvention. Definitely speaking, providing these embodiments makes thedisclosure complete and entire, and fully indicates the scope of thepresent invention to a person of ordinary skill in the art. In thedrawings, the shape and size for clear illustration purposes may beexaggerated, and the same reference numerals are used for showingidentical or similar components across the whole of the drawings.

According to exemplary embodiments of the present invention (thisdisclosure), the present invention discloses a color regulating devicefor illumination, a color regulating method, and an apparatus using thecolor regulating device. In summary, a “light valve” such as liquidcrystal (LC) cell or color changing glass capable of continuouslyadjusting the light transmission rate (ratio of incident light tooutgoing light), and a color adjusting structure having patternablephosphor layer or wavelength-band converting element, are cooperated toaccurately regulate color temperature to make the device and apparatusof the present invention have a “continuous” and “accurate” function ofregulating color temperature of a light source. Furthermore, accordingto the embodiment of the present invention, using a single light sourceto accurately adjust the spectrum distribution or wavelength band offinal outgoing light to achieve the light source effect that was onlyachieved by multiple light sources in the past.

So-called “accurate” adjustment of color temperature means using thecolor regulating device for illumination according to the presentinvention to control the color temperature of the mixed outgoing lightfor illumination within an inaccuracy of ±50K, adjust along BBL (theregion of Planckian Locus) to comply with the standard of ANSI C78.377A.

The wavelength-band regulating method according to the present inventionnot only employs more than one phosphor to cooperate with light valvingmeans to adjust each light flux to mix the light with desired colortemperature but also uses subtraction means of wavelength band (forexample, material absorbing specific wavelength band is added) to absorbspecific wavelength band to lower the luminous flux so that colortemperature or resultant wavelength band of light is adjusted.

The term “equivalent” of the present invention means that wavelengthbands of light are identical or substantially identical. It mainlyindicates that when incident light passes through a material, major partof the wavelength band thereof is kept unchanged (the same) and onlyminor part of the wavelength band is affected by the material causingpossible refraction/diffusion/reflection/scattering/interference to makethe wavelength to slightly diverge from the original wavelength band butstill belong to the light of the same wavelength band.

The following fact is different from “equivalent.” When incident lightpasses through the wavelength-band converting material (for example,phosphor) or other wavelength-band converting element (for example,interference structural element), the wavelength band of outgoing lightsignificantly shifts from that of the incident light, causing thewavelength band of the outgoing light different from the wavelength bandof incident light.

According to the device, apparatus and method of embodiments of thepresent invention, as shown in FIG. 3, a color regulating device forillumination 300 comprises a light to be regulated for color temperature(emitting from a first light source 301), a light-valving structure 303,and a color-adjusting structure 302. The light-valving structure 303 andthe color-adjusting structure 302 at least partially overlap on atraveling path of the light, forming at least one overlapping structure.

As shown in FIG. 3, a part of the light emitting from the first lightsource 301 becomes a first incident light 305 of the light whichinteracts with the light-valving structure 303. After the interaction(i.e., transmitting through in the embodiment) with the light-valvingstructure 303, the first incident light 305 becomes a first outgoinglight 306 from the light-valving structure 303. The light-valvingstructure 303 is employed to regulate a ratio of luminous flux of thefirst incident light 305 and the first outgoing light 306 of the lightinteracted with the light-valving structure.

In FIG. 3, another part of the light emitting from the first lightsource 301 becomes a second incident light 307 of the light interactedwith the color-adjusting structure 302. After through thecolor-adjusting structure 302, the second incident light 307 turns intoa second outgoing light 308 from the color-adjusting structure 302. Thecolor-adjusting structure 302 is employed to covert the second incidentlight 307, which has a first wavelength band, of the light interactedwith the color-adjusting structure to the second outgoing light 308which has a second wavelength band.

Referring to FIG. 3, further another part of the light emitting from thefirst light source 301 passes through the overlapping structure formedby the overlapped portion of the light-valving structure and thecolor-adjusting structure on the traveling path of the light. In view ofthe direction of traveling path of the light, the color-adjustingstructure 302 is disposed in front of and partially overlapped with thelight-valving structure 303, such that a part of the second outgoinglight 308 passing through the color-adjusting structure 302 enters thelight-valving structure 303 and becomes the first incident light 305,and then emits from the light-valving structure 303. Such passingthrough both the light-valving structure 303 and the color-adjustingstructure 302 (i.e., the overlapping structure) coverts the light into athird outgoing light 309 having a second wavelength band and a luminousflux different from the incident light into the overlapping structure.

Eventually, the first outgoing light 306, the second outgoing light 308,and the third outgoing light 309 are mixed to form a hybrid light havinga color temperature different from that of the light emitting from thefirst light source 301.

In an embodiment according to the present invention, the hybrid lightmixed from the first outgoing light 306, the second outgoing light 308,and the third outgoing light 309 is further mixed with the originallight 304 emitting from the first light source 301 but without beinginteracted with either the light-valving structure 303 or thecolor-adjusting structure 302.

According to the device, apparatus and method of embodiments of thepresent invention, the second wavelength band covers the firstwavelength band; that is, the second outgoing light 308 still includes aportion of the unconverted wavelength of the first light source 301. Inother words, after the light from the first light source 301 enteringthe color-adjusting structure 302 and becoming the second incident light307, a portion of the light is converted in wavelength band by thewavelength-band converting element of the color-adjusting structure 302,but another portion of the light remains in the wavelength band of thesecond incident light 307 (i.e., the wavelength band of the first lightsource 301). As such, the second outgoing light 308 from thecolor-adjusting structure 302 has the second wavelength band which isboarder than and covering the first wavelength band of the secondincident light 307.

As shown in FIG. 4, according to the device, apparatus and method ofembodiments of the present invention, a color regulating device forillumination 400 further comprises a second light source 411 emittinganother light 410. The another light 410 is mixed with the firstoutgoing light 406, the second outgoing light 408, the third outgoinglight 409, and the original light 404 emitting from the first lightsource 401 but without being interacted with either the light-valvingstructure and the color-adjusting structure, so as to form a hybridlight having a color temperature different from that of the originallight.

According to another embodiment of the present invention, the lightsource is a combination of a plurality of light sources with differentcolors, or a white light source associated a light source(s) with asingle or different colors.

FIG. 5 shows another embodiment of the present invention, thecolor-adjusting structure 502 is completely overlapped by thelight-valving structure 501 on the traveling path of the light, suchthat the entire second outgoing light from the color-adjusting structureenters the light-valving structure 501 becoming the first incidentlight.

Referring to FIG. 6, according to another embodiment of the presentinvention, in addition to the light-valving structure 601 having thecolor-adjusting structure 604 on the bottom surface facing the incidentdirection of the light source 603, the light-valving structure 601 hasother color-adjusting structure 602 therebesides on a planeperpendicular to the direction of the traveling path of the light.

According to embodiments of the present invention, the positions of thelight-valving structure and the color-adjusting structure relative tothe light source is adjustable depending on demands. For example, thereverse sequence of the light emitting from the light source passing thecolor-adjusting structure first and then the light-valving structure isalso illustrative and applicable in the aforementioned embodiments, bysimply placing the light-valving structure in front of thecolor-adjusting structure on the traveling path of the light.

According to an embodiment of the present invention, the light-valvingstructure is to use change of an electrically induced substance tofurther affect its optical properties such as transmittance andrefractive index. The aforementioned change of the electrically inducedsubstance includes but is not limited by: (1) oxidation reduction; (2)electrically induced phase transition; (3) the electrically inducedchange in structure or density of substance; (4) electrically inducedchange in hydrophility/hydrophobicity of substance. With theaforementioned change of the electrically induced substance, a controlthat affects quantity of transmittance, refraction and reflection of aspecific spectrum region (such as a certain color) can be achieved. Inother words, a light valve is able to selectively magnify or absorb aspecific wavelength to serve a light-valving element for only a specificwavelength band of incident light instead of all incident light sourceswith other wavelength bands.

According to embodiments of the present invention, any members capableof controlling the intensity ratio of the incident/outgoing lightinteracted therewith in a continuous and precise manner are allpotential candidates, such as a liquid crystal layer structure, a microelectro mechanical system (MEMS) assembly, an electronic paper, apiezoelectric device/material, an electrowetting element, a colorchanging glass or the combination thereof. The members can be configuredin a three-dimensional structure.

According to an embodiment of the present invention, the light-valvingstructure controls the transmission ratio of incident/outgoing lightthrough a specific area of the light-valving structure, and then thecolor-adjusting structure accepts the controlled outgoing light of thelight-valving structure into the wavelength-band converting element toproceed a wavelength conversion. As such, all the controlled outgoinglight and uncontrolled outgoing light (including a portion of theoriginal light from a light source) are mixed so as to regulating thecolor temperature of an intended hybrid light. As embodiments of thepresent application, the wavelength-band converting element is awavelength-band converting material or a wavelength-band convertingstructure unit.

According to an embodiment of the present invention, the wavelength-bandconverting material of the color-adjusting structure comprises aphotoluminescence (PL) material.

So-called “photoluminescence (PL) material” means when such materialreceives electromagnetic wave irradiation (for example, blue light,ultraviolet light, laser beam, X-ray or electron beam) and absorbs lightwith sufficient energy, electrons acquire sufficient energy and jump tothe excited state. The electrons release energy when falling down to theground state. In case the released energy is in form of light, suchprocess is called “photoluminescence effect.”

In the aforementioned materials with PL characteristics, there are otherreplaceable materials except for phosphors. Basically, any material thatis capable of converting incident light to outgoing light with aspecific wavelength band may be used, for example: (a) fluorescent dyeswith photoluminescence effects (for example, DCM, CV670, etc. (types areas shown in “Exciton” website, www.exciton.com/wavelength_chart.html));(b) wavelength-band blocking type materials: pigments and dyes. Ageneral dye has characteristics of completely absorbing light with aspecific wavelength band so can filter off unnecessary wavelength bandand leave the light with a specific wavelength band to mix with thesource light. Replacing phosphors with blocking type materials causesconditions of lower light emitting efficiency but the blocking typematerials are still candidates for the replacement of the phosphors ofthe present invention.

According to embodiments of the present invention, the phosphor isselected from the group of an oxide phosphor, an oxynitride phosphor, anitride phosphor, a zinciferous compound phosphor, a semiconductorphosphor, an organic phosphor, a photoluminescence dye and combinationthereof.

According to embodiments of the present invention, the dye is anabsorption type dye, a photoluminescence type dye or the combinationthereof.

Furthermore, additives in the liquid crystal cell may be quantum dots(for example, GaAs, CdSe, CdS, etc.) having photoluminescencecharacteristics, or may be combination of other phosphor, dye, pigmentwith additional quantum dots. When size of the material is smaller thana degree of 100 nm or lower, the material may be called “quantum dot” aslong as the size of the material is smaller than its Fermi wavelength.Because electrons of a quantum dot are confined and dominated by the“quantum confinement effect”, energy level thereof generatesdiscontinuous states as presented in atoms. Therefore, the quantum dotis also called artificial atom. Different size generates differentenergy levels so that changing the size of a quantum dot will be able tochange the wavelength of visible light radiated due to excitation by“electron transition”, i.e. the color of light. However, because thephotoluminescence effect of the quantum dot is size dependent typeinstead of material property, using the quantum dot as a wavelength-bandconverting material in indoor illumination is not efficient and the costthereof is high. Therefore, the quantum dot can only be used forassisting color adjustment and be doped in the liquid crystal layer orthe wavelength-band converting materials according to the presentinvention.

According to an embodiment of the present invention, the wavelength-bandconverting structure unit is a member made of cholesteric liquidcrystals, blue phase liquid crystals, holographic polymer-dispersedliquid crystals (H-PDLC), an electrowetting element, or a microelectro-mechanical assembly.

Basically, “parameters” that can be used for color adjustment of anexemplary embodiment of the present invention includes but is notlimited by: “phosphor coating area/color ratio”, “drivingelectrodes/phosphor relative position and their areas”, “area ofpolarizer/relative positions and directions of polarizers/polarizer arearelative to phosphor”, “normally white/normally black (NW/NB)”, “colorof light source”, etc. After each parameter is optimized, such outgoinglight will be accurately adjusted between the two color temperatures ofcold white and warm white light. For example, a parameter condition maybe the size of region occupied by the phosphor or doping concentrationand quantity. If the luminous flux of blue light (or the luminous fluxof yellow light after wavelength-band conversion) through the liquidcrystal layer structure is excessively high and results in that thecolor temperature cannot be adjusted to white light with a specificcolor temperature, the aforementioned phosphor parameter condition canbe adjusted to change a mixing ratio of luminous fluxes of differentwavelength bands so as to achieve the specific color temperature ofwhite light.

In embodiments of the present invention, to decide to use a light sourcewith a specific color temperature, the cooperation of colors ofphosphors (a wavelength-band converting material) is referred to the CIE1931 color space chromaticity diagram. As shown in FIG. 1, the curve inmiddle of the chromaticity diagram is black body locus (BBL). Such curvepasses through a white light region mixed by red, green and blue primarycolors. In the region, a right side region is warm white light, and aleft side region is cold white light. A common white light source forillumination is valuable for illumination application only when thechromaticity coordinate thereof is located within the region. Therefore,to choose chromaticity of a light source and color of a phosphor, aconnecting line between locations of the chromaticities of the lightsource and phosphor on the chromaticity diagram should pass through suchregion. If the connected line further intersects the BBL at anintersection point, we can locate the chromaticity of the mixed lightright on the intersection point by adjusting intensity of the lightsource or intensity of the excited light of the phosphor. For example,line bb′ as shown in FIG. 1 is composed of two end points of a blue LEDlight source (chromaticity coordinate b) having a wavelength of 450 nmcooperating with a yellow phosphor (chromaticity coordinate b′) with theCIE 1931 chromaticity coordinate (CCx, CCy)=(0.4204, 0.5563). Any pointon the line bb′ may be acquired by mixing the light sources of the twoend points with a different mixing ratio. The color temperature of theintersection point of line bb′ and BBL is α. Furthermore, line cb may becomposed of two end points of the 450 nm blue light source having thechromaticity coordinate at point b cooperating with a pure yellowphosphor whose chromaticity coordinate is at point c. The colortemperature of the intersection point of line cb and BBL is 3, whichbelongs to a chromaticity coordinate of warm light. Likewise, a purplelight source or green light source can be selected to change the leftside end point of the above-mentioned line to further adjust the colortemperature of the intersection point between the line and the BBL.

However, although the continuity of wavelength distribution on thespectrum by merely using the yellow phosphor cooperating with the blueLED to generate white light is extremely close to that of true sunlight,there is still a space between the aforementioned spectrum and thespectrum of sunlight, for which a main reason is that lack of a redlight source of the three primary colors causes a space in visible lightspectrum after the color lights are mixed and results in the low colorrendering of the light source. At this time, using a phosphor with asecond color (for example, red) (i.e. a PL material for converting atleast part of incident light to outgoing light with a differentwavelength band) or doping other dye or pigment different from theyellow phosphor in the liquid crystal cell can make the transmittedlight passing through the liquid crystal element have an additionalspectrum of certain wavelength band (i.e., the third light being added)for improving color rendering of hybrid light.

In an embodiment of the present invention, the light source is selectedfrom the groups consisting of a light emitting diode (LED), anincandescent lamp, a halogen lamp, sunlight, a cold-cathode fluorescentlamp (CCFL), fluorescent lamp and combination thereof. In addition to atleast one colored light sources, a light source can also use a whitelight source, or use a colored light source to cooperate with a whitelight source. An exemplary embodiment according to the present inventionaccurately adjusts the light-valving structure of the color regulatingdevice to make the color temperature of a white light source with colorshift regulated into the BBL region. Likewise, with regard to a whitelight source (not limited in LED light sources) of which chromaticitycoordinate is already known, a phosphor having a corresponding lightcolor may be selected so that light of the white light source and lightgenerated from the excited phosphor are mixed to form a white lightwithin a predetermined chromaticity extent. Further, controlling thelight-valving structure to change the luminous flux by applied voltagemakes the mixed light switch between the original white light and warmwhite light.

The light sources used in the color regulating device and colorregulating method for illumination of the present invention basicallymay be existent conventional light sources for illumination, of whichthe only requirement to be fulfilled is that intensity of the lightsource is sufficient to make a phosphor act to convert a wavelength bandof at least part of incident light to another different wavelength bandof outgoing light. LED light sources are taken for example. In thecurrent high-power LED products, except for blue light LED fabricationprocess that tends to mature, other color light LEDs has lower lightemitting efficiency in comparison with blue light LEDs because of theunstable process thereof. Moreover, these LEDs usually have poor productyield in the process of mass production. It frequently happens thatsamples in the same batch of products depart from a predetermined colortemperature region. Even excellent and qualified LED products, whencooperating with phosphors for mixing white light, probably depart fromthe predetermined color temperature region because of errors in samplingof phosphors. White light LEDs are limited by these two uncertaintyfactors so that the output thereof is greatly decreased. Defectiveproducts can only be sold at lower prices. However, if the colorregulating device for illumination of the embodiment according to thepresent invention is used to adjust the white light, the aforementionedconditions will not happen. As long as a connecting line betweenchromaticity coordinates of LED and phosphor in the chromaticity diagrampasses through a region as shown in FIG. 2, the transmittance of theliquid crystal can be controlled by fine adjusting voltage to achievethe purposes of accurately controlling the chromaticity coordinate tofall into a specific region.

In an embodiment according to the present invention, the liquid crystallayer structure serving as a light valve has at least one liquid crystalcell. So-called “liquid crystal layer structure” here has transparentelectrodes situated between two light-permeable substrates, a liquidcrystal layer including liquid crystal molecules, and two optionalpolarizers respectively attached to outsides of the light-permeablesubstrates. “Liquid crystal cell” means that in the liquid crystal layera bias voltage can be applied independently to adjust an electric fieldthrough the liquid crystal layer to further change a twist and/or tiltangle of liquid crystal molecules to achieve purposes of adjustinggrayscale of the liquid crystal cell.

Liquid crystals are rod-like molecules and are capable of redirectingpolarization direction of light or directly blocking part of light frompassing. At present, common liquid crystals generally contain threadlikeliquid crystals (i.e. nematic LCs), smectic liquid crystals,ferroelectric liquid crystals, cholesteric liquid crystals (CLCs), bluephase liquid crystals, discotic liquid crystals and polymer disperseliquid crystals (PDLCs). Nematic liquid crystals are most widely used inthe daily life, for example, displays.

It is diversified for using liquid crystals on current displays.Furthermore, according to different design, liquid crystal molecules maybe operated by various driving modes, such as twisted nematic (TN,wherein TN liquid crystal molecules are rotated for 90 degrees or othersuitable angles in practice) mode, super twisted nematic (STN, whereinliquid crystals are rotated for larger angles like 240 to 270 degrees,etc.) mode, in-plane switching (IPS) mode, fringe field switching (FFS)mode, vertical alignment (VA) mode, multi-domain vertical alignment(MVA) mode, optically compensated bend (OCB) mode, electricallycontrolled birefringence (ECB) mode and axially symmetric alignedmicrocell (ASM) mode, etc. The most basic framework is 90° TN mode andother modes respectively provide particular advantages, for example,wide view angle, fast response time, etc.

FIG. 7 shows a schematic diagram of a liquid crystal layer structure700. Opposite surfaces of two light-permeable substrates 704, 705 arecoated with transparent conductive electrodes of indium tin oxide (ITO)701, 702 for applying voltage to build an electric field between thelight-permeable substrates; alignment layers 711, 712 are applied ontothe ITOs and each alignment layer has fine grooves so that the groovesof the alignment layer are used to align liquid crystals; spacers 703are located between and evenly partition the two light-permeablesubstrates, and then the liquid crystal layer 706 is filled with liquidcrystal (LC) molecules. Subsequently, there may be differences in theuse of demand, in the case of 90° TN LC mode, two polarizers 707, 708,two polarizing directions of which are orthogonal to each other in 90°TN liquid crystal, are attached respectively on upper and lower sides ofthe whole element. The relative polarizing directions of the twopolarizers may change with demands in practice. When the ITO electrodeson the upper and lower light-permeable substrates are applied withadequate voltage, the electric field built in the liquid crystal cell isable to drive the liquid crystal molecules to continuously twist andtilt to correspond to the magnitude of the electric field and to befinally parallel to the direction of the electric field. After anincident light passes through the first polarizer, the light becomes alinearly polarized light which then passes through the liquid crystalmolecules in the liquid crystal layer. The liquid crystals change theirorientations under bias voltage, causing the polarized state of outputlight will be changed accordingly. Cooperating with the linearpolarization effect of second polarizer, outgoing light will generatedifferent light intensity for representing grayscale. The aforementionedis the most basic liquid crystal cell of the 900 TN framework. With suchembodiment of the liquid crystal layer structure, a flux ratio ofincident light to outgoing light may be adjusted for a “light valve” ina color regulating method of the present invention.

According to light-permeable state or non-light-permeable state of theliquid crystal cell without applied voltage, the operation mode of theliquid crystal cell may be classified into normally white (NW) mode andnormally black (NB) mode.

FIGS. 8A and 8B shows an exemplary embodiment according to the presentinvention. TN type liquid crystals are used to explain the basicframework of NW and NB modes and light-permeable operation mode. In FIG.8A, the grooves of the upper alignment layer and the grooves of thelower alignment layer are perpendicular to each other, which will makethe liquid crystal molecules twist for 90 degrees between suchsubstrates to further make the polarization direction of passedpolarized light to twist for about 90 degrees along the twist of theliquid crystal molecules; therefore, by arranging the upper and lowerpolarizers to be perpendicular to each other and arranging the alignmentdirection of the liquid crystals of each surface to be parallel to thecorresponding polarizer, incident light can easily pass through thewhole liquid crystal cell to form a light-permeable state (so-called“bright state”). A TN liquid crystal element in the light-permeablestate without applied voltage is called NW TN liquid crystal element.The only difference between the NW mode and NB mode is the relativepositions of the two polarizers; changing the polarization directions ofthe two polarizers perpendicular to each other to polarizationdirections paralleling to each other turns to the NB mode (as shown inFIG. 8B). If a fully light-permeable state is presented in a defaultstatus without applying voltage, light energy loss and voltage drivingconsumption can be reduced. However, in application, designs of NB modeliquid crystal cells can be employed depending on the actual demand.

According to the present embodiment, liquid crystal molecules 706 in theliquid crystal layer structure 700 in FIG. 7 use cholesteric liquidcrystals (CLCs). CLCs are tri-stable state liquid crystal materials.With an increased applying voltage onto the liquid crystal cell in theliquid crystal layer, CLCs change from planar phase to focal conicalphase and then finally become homeotropic phase.

Because CLC is switched between the focal conical phase and thehomeotropic phase, the CLC element may be switched fromnon-light-permeable state to light-permeable state. Therefore, when CLCis used to serves as liquid crystal molecules material in the liquidcrystal cell, the purpose of adjusting luminous flux of the liquidcrystal layer structure can be achieved by only changing the voltageapplied to liquid crystal cell without the need of using polarizers 707,708. In addition, in the planar phase of CLCs, LC molecules form ahelical twist arrangement reflecting a specific wavelength of light.When the CLCs are used to serve as a light-valving structure, thelight-valving structure itself can also serve as a color-adjustingstructure.

Another alternative embodiment uses dye type liquid crystal moleculematerial and may simultaneously serve as a light-valving structure and acolor-adjusting structure. That is the light-valving structure andcolor-adjusting structure are an integral structure.

In an alternative embodiment according to the present invention, whenliquid crystal molecules in the liquid crystal layer structure use thetwisting pitch of the CLC molecules up to hundreds of nanometer,regional blue phase liquid crystals with double twist structure aregenerated. As the blue phase liquid crystals stabilize themselves via apolymeric network, the range of working temperature is expanded (in needof no alignment for the blue phase liquid crystals). Further, becausethe structure of blue phase liquid crystals is similar to that of ageneral crystal, it can reflect out a specific wavelength of light(depending on the lattice length generated by the double twiststructure) and can be configured as the light-valving structure as wellas the color-adjusting structure at the same time.

In another alternative embodiment according to the present invention,liquid crystal molecules of the liquid crystal layer structure use PDLCserving as a grayscale adjusting structure in an electronic paper (or anelectronic book). Because the PDLC can be switched between scatteringand transparent states to achieve the non-light-permeable state orlight-permeable state, therefore, driving the PDLC needs neitherpolarizers nor alignment layers. In other words, an electronic paperwith the PDLC for controlling grayscale may also serve as a light valveof the present invention. Other electronic papers, e.g., a rotating-ballelectronic paper, electrophoretic electronic paper (i.e., an E-inkswitching film), and color electrowetting switching element, areembodiments of the present invention. The dyed electronic papers canalso be used as the color-adjusting structure at the same time. In thesame manner, a PDLC doped with fluorescent dye can be served as thecolor-adjusting structure according to an embodiment of the presentinvention. Further, a holographic PDLC (H-PDLC) material can not onlyserve as the light-valving structure, but the material itself is alsothe color-adjusting structure according to an embodiment of the presentinvention, in that its structure of molecular arrangement is able toreflect a certain wavelength of light.

Furthermore, PDLC can be driven by AC voltage to change its grayscale.Changing a driven frequency can only help to improve the response timeof PDLC. However, such driving technique is different from the drivingmethod of the “frequency responsive” nematic LCs, because the grayscaleof these nematic LCs is varied by tuning the “frequency” at a constantapplied voltage.

FIG. 9 shows a curve of applied voltage value versus light transmissionvariation through the liquid crystal cell. Here, the magnitude of thedriving voltage is only exemplified for convenience of description, theactual driving voltage will depend on liquid crystal types and species,and other relevant parameters. It shows a liquid crystal cell from abright state to a dark state, wherein a vertical axis indicatestransmittance (T %) and a horizontal axis indicates voltage (V) appliedto the electrodes on the two sides. The bright state (often defined asthe light transmittance >90%) is the state with an applied voltage lowerthan 1.75 V in the figure, and the dark state is the state with theapplied voltage larger than 3.5 V. The state in grayscale (the regionbetween two dashed lines in FIG. 9) corresponds to the extent of appliedvoltage from 1.75 to 3.0 V. The light is from fully bright state tofully dark state. “Fully bright” means white and “fully dark” meansblack so that a “continuous” transition state between the fully brightstate and the fully dark state is called “grayscale.” If voltage isadjusted within such extent, light transmission quantity can becontinuously controlled by slightly increasing or decreasing voltage tomake the liquid crystal cell as a light valve.

In another embodiment according to the present invention, as shown inFIG. 7, the two polarizers 707, 708 are used respectively on theoutsides of the two light-permeable substrates. Besides conventionalpolarizers, “non-absorption type polarizers” may also be employed tolower luminous flux loss during the adjustment of light sources. Theprinciple of non-absorption type polarizers is to use multilayer filmsto interfere with PE wave and PM wave (these two waves are perpendicularto each other) to make PE wave disappear and PM wave increase so that afunction of polarization is achieved. The non-absorption type polarizerincludes the non-absorption scattering polarizer. It defines the lighttransmission axis through the matching of two refractive indices of hostand guest materials in polarizer, while the non-transmittance axisperpendicular to the transmission axis is produced by the refractiveindex mismatch of host and guest materials, thereby forming thepolarization function. The incident light disappears in thenon-transmittance axis due to multiple interferences and can berecovered for the reuse as incident light. In general, non-absorptiontype polarizers may raise brightness up to 1.5 times or larger so thatnon-absorption type polarizers can be used to increase lighttransmittance for improving illumination efficiency.

FIG. 10 shows a color regulating device 1000 for illumination accordingto an exemplary embodiment of the present invention. As shown in FIG.10, a liquid crystal layer 1006 composed of liquid crystal molecules andspacers 1015 is sandwiched between a first light-permeable substrate1004 and a second light-permeable substrate 1005 to form a liquidcrystal layer structure 1010. The liquid crystal layer 1006 has multipleliquid crystal cells (LC cell) 1022 for controlling grayscalerespectively, which can cooperate with a pair of transparent electrodes1001, 1002 on the light-permeable substrates 1004, 1005 to apply voltageto the liquid crystal cells 1022 for changing the twist and/or tilt ofliquid crystal molecules in the liquid crystal cells 1022 between thetransparent electrodes. Two polarizers 1007, 1008 are respectivelyattached to outsides of the light-permeable substrates 1004, 1005relative to the liquid crystal layer. Arrangement of the polarizers andthe alignment directions of liquid crystal molecules on two surfaces ofthe liquid crystal layer is set to normally white (NW), in other words,the liquid crystal cell 1022 without applied voltage is light-permeable.By changing the applied voltage to each liquid crystal cell 1022,grayscale of the liquid crystal cell 1022 is varied continuously tofurther control the luminous flux of outgoing light through each liquidcrystal cell 1022.

In the embodiment according to the present invention, the colorregulating device for illumination further comprises at least onetransparent plate which is abutting or not abutting the surface of thefirst side of the first light-permeable substrate, or abutting or notabutting the surface of the second side of the second light-permeablesubstrate in the liquid crystal layer structure. The transparent platemay be a rigid or a curved object or a flexible sheet to facilitatedirectly coating wavelength-band converting PL material on an accurateposition on a surface of the flexible sheet by a roll to roll coatingmethod or dispersing the wavelength-band converting PL material in theentire transparent part. The transparent plate may abut or combine withthe liquid crystal layer structure depending on the demands. Thetransparent plate may also be separated from the liquid crystal layerstructure, located between the light source and liquid crystal layerstructure or located at a side of the liquid crystal layer structureopposite to the light source. The transparent plate may be selected frombut not limited to the group consisting of: glass, quartz,polimethylmetharylate (PMMA), polystyrene (PS), methylmethacrylate-co-styrene (MS), polycarbonate (PC) and combinationthereof. The first and second light-permeable substrates of the liquidcrystal layer structure may adopt the aforementioned materials. If theflexible materials, e.g., PMMA, PS and PC, are used for thelight-permeable substrate of the liquid crystal layer structure, suchliquid crystal layer structure is configured as a flexible liquidcrystal layer structure unit.

Furthermore, a wavelength-band converting material may be coated (e.g.,sputtering or spin coating) on a selected region or all area of thetransparent plate depending on the demands to convert the wavelength oflight on the specific region or all regions of the transparent plate formixing light during color adjustment.

FIGS. 11A and 11B are cross sectional schematic views along line DD′explaining for a color regulating method using the color regulatingdevice of the embodiment in FIG. 10. In the figures, an area A is coatedwith a yellow phosphor layer 1130 (strictly in definition being agreen-yellow phosphor, but is referred as the yellow phosphor layer inshort for convenient description hereafter) and an area B has nophosphor coating layer. Referring to FIG. 11A, an blue light LED 1131 isused as an light source, and a liquid crystal cell 1122 is configured asthe light-valving structure to control the luminous flux of a portion ofthe original light from the blue light LED 1131. Alternatively,referring to FIG. 11B, the liquid crystal cell 1122 is configured as thelight-valving structure to control the luminous flux of yellow/bluelight transmitting through the area A (there are still a certain amountof the original blue light not converted as passing through the area A),so as to accurately control the ratio of the mixed blue light and yellowlight from the areas A and B and obtain the hybrid white light with adesired color temperature. By controlling the liquid crystal cell 1122,the luminous flux of incident light entering the yellow phosphor layer1130 of the region A and the luminous flux of incident light enteringthe region B not coated with the phosphor can be accurately adjustedrespectively. The light from the blue LED light source partially passesthrough the region B without the yellow phosphor layer, and partiallypasses through the area with the yellow phosphor layer but is notconverted, and then both are mixed with yellow outgoing light convertedby the yellow phosphor layer to acquire the desired color temperature ofwhite light. In the figures, although four LED light sources are shown,the number is for illustration only but is not limited. Further, thearea of the yellow phosphor layer 1130 may or may not (i.e., larger orsmaller than) correspond to the area of the respective liquid crystalcells 1122. The total area ratio of the yellow phosphor layer-coatedregion A and the uncoated region B depends on the demands in the actualapplications or the desired color temperature to be obtained. Moreover,in the present embodiment, the wavelength-band converting material isthe aforementioned yellow phosphor material, i.e., the firstwavelength-band converting material. The first wavelength-bandconverting material may be coated on at least a portion of a surface ofthe transparent plate, or be dispersed inside the transparent plate. Thetransparent plate may abut or not abut the liquid crystal layerstructure to form the separate structure. Alternatively, the firstwavelength-band converting material may be disposed or dispersed in theliquid crystal layer to from the integral structure.

According to another embodiment, the first wavelength-band convertingmaterial is coated on the surface of the first or second side of thefirst light-permeable substrate, or is coated on the surface of thefirst or second side of the second light-permeable substrate, so as toform the separate structure.

Because electrodes in the region A and region B in FIG. 10 areindependent from each other, the liquid crystal cells corresponding tothe different regions can be controlled individually. FIG. 11A indicatesa light transmittance of driving the blue light passing through theregion B. FIG. 11B indicates a yellow/blue light transmittance ofdriving the region A of the yellow phosphor (there are a certain amountof the original blue light not converted to yellow light as passingthrough the region A). The controlling modes in the two regions may becontrolled with individual applied voltages simultaneously (dual drivingmodes), which has an advantage of increasing variation extent of colortemperature of mixed light. Line pq in FIG. 12 is composed of two endpoints of a blue LED light source with a wavelength of 450 nmcooperating with a yellow phosphor with the CIE 1931 chromaticitycoordinate (CCx, CCy)=(0.4204, 0.5563). The chromaticity coordinate prefers to a blue light purely from the region B, and the chromaticitycoordinate q refers to a mixed blue/yellow light purely from the regionA. Any point on the line pq may be acquired by mixing the light sourcesof the two end points with a different mixing ratio. The colortemperature of the intersection point of line pq and BBL is γ. However,as shown in FIG. 12, it is assumed that the color temperature γ of aninitial setting is under a condition that all regions are not drivenwhile yellow light and blue light are mixed to white light. When appliedvoltage in the yellow light region increases, light transmittance of theyellow light decreases gradually; in the meanwhile, mixed light movesfrom the chromaticity coordinate γ of the original white light towardthe chromaticity coordinate p to gradually become cold white light. Whenthe applied voltage increases to the close (dark state of LC cell) ofthe yellow light region, yellow light is completely blocked, in the meanwhile, only the light source of blue light (chromaticity coordinate p)is left (as shown in FIG. 11B), light that is transmitted out is bluelight.

In an alternative embodiment, a layer of yellow phosphor is coated overa portion of a region above the liquid crystal cells, and the ITOelectrodes and polarizers under the portion of the region are remainedfor controlling the luminous flux of the light transmitted through theyellow phosphor. The ITO electrodes and polarizers located on anuncovered region other than the portion of the region are completelyremoved, such that the liquid crystal cells corresponding to theuncovered region are not controlled by the applied voltage. That is, theuncovered region is always permeable to the blue light and notinfluenced by the polarizers resulting in any intensity loss. As workingexamples, the remained ITO electrodes and polarizers occupy less than25% of the total area of all elements. As far as a polarizer having50-60% blocking rate is concerned, the loss of the total luminous fluxis around 13-15%. If using the non-absorption type polarizer, the lossof the total luminous flux can be reduced below 7-10%.

In an alternative embodiment, the a layer of yellow phosphor is coatedover a portion of a region above the liquid crystal cells, and the ITOelectrodes and polarizers under the portion of the region are removed,and the ITO electrodes and polarizers located on an uncovered regionother than the portion of the region are remained for controlling theluminous flux of the blue light transmitted through the uncoveredregion. The luminous flux of the transmitted light of the blue LED canbe regulated from fully permeable to fully blocking, and then thetransmitted light is mixed with the yellow/blue light emitted from theyellow phosphor. As to the region with the ITO electrodes, whichoccupies the same area as that of the polarizer among the all elements,its area depends on the actual needs or the desired color temperature tobe obtained.

In an alternative embodiment, an orange-yellow phosphor is used toreplace the yellow phosphor, such that the hybrid light after beingmixed with the light from the blue LED light source is closer to thewarmer color light. Further, as to the color light source (>5,300 K),the yellow phosphor and/or orange-yellow phosphor is used to adjust theoutgoing light to a cold light (>3,300 K), a warm light or a even warmercolor light. On the other hand, as an alternative embodiment, a purplelight source is used and the phosphor is a green-yellow phosphor, or agreen light source is used and the phosphor is a red phosphor, and adesired hybrid white light can thus be mixed.

According to an alternative embodiment of the present invention, twopolarizers are arranged to a normally black (NB) mode that liquidcrystal cells are in the dark-state condition when voltage is applied.The current embodiment, different from the embodiments illustrated byFIGS. 11A and 11B, has the two polarizers arranged to be parallel, asshown in FIG. 8B. Therefore, light rays cannot pass through the liquidcrystal cells (in the NB mode) at all without applying voltage. As shownin CIE 1931 chromaticity diagram of FIG. 13, the initial setting ofcolor temperature x is under a condition that all of the regions aredriven by voltages while yellow light and blue light are mixed intowhite light (where the color temperature is not accidentally in the BBLcurve). When all of the regions are first driven and then the voltage inthe blue light region gradually decreases, blue light is blockedgradually. The mixed light gradually changes from the original whitelight (color temperature x) and becomes a close-to-yellow light (colortemperature B) as shown in FIG. 13, wherein the color temperaturemovement in the CIE 1931 chromaticity diagram is as a path 2 in FIG. 13,and intersects the BBL curve at the color temperature γ which belongs tothe cold white light in color temperature. Therefore, regulating theliquid crystal can finely and precisely the desired color temperature tothe BBL curve. Alternatively, if a pure yellow phosphor is used toreplace the phosphor material, the hybrid light gradually moves from theoriginal white light to the warm light in the BBL curve (i.e., near thecolor temperature β in FIG. 1). On the contrary, when voltage in theyellow light region gradually decreases, light transmittance of theyellow light decreases gradually, in the meanwhile, mixed lightgradually changes from the original white light to bluish cold light.When the voltage in the yellow light region is completely turned off,yellow light is completely blocked, in the mean while, only the lightsource of blue light is left, light that is transmitted out is bluelight. Adjusting the voltage of the yellow light region makes colortemperature change along a path 1 in the CIE 1931 chromaticity diagramin FIG. 13. Thus, the color temperature of the transmitted lightgradually moves from the chromaticity coordinate A to the chromaticitycoordinate B in FIG. 13. In other words, the fully blue light graduallybecomes a close-to-yellow light, that is to say, the extent of colortemperature of the light source crosses over the whole line AB.

In the embodiment according to the present invention, distribution ofthe yellow phosphor may be as shown in FIG. 14. FIGS. 14A-F demonstratevariable coating patterns of the phosphor layer. A slash region in thefigure indicates a distribution region of the yellow phosphor layer. Bymeasuring the luminous flux per unit area of transmitted light of eachof the yellow phosphor region and the blue light LED region, a ratio ofregion in which the yellow phosphor needs to occupy may be preciselycalculated so that mixed light can acquire a predetermined chromaticity.Afterwards, the luminous flux of the transmitted light can be adjustedby applying voltage to drive the liquid crystal cell (the light-valvingstructure). For example, the luminous flux of the transmitted blue lightor luminous flux of the transmitted yellow light may be adjusted forfine adjustment of chromaticity to achieve desired color temperature.

FIG. 15 shows a color regulating device for illumination according to anembodiment of the present invention. In the present embodiment, theliquid crystal cells are outwardly divided into three regions A, B, andC and driven by various voltages. By applying the various voltages frominside to outside, the luminous fluxes of the respective liquid crystalcells are regulated to continuously change their grayscales. As such,the outer parts of the LED light source can be reduced due to the issueof the space color shift in LEDs. In another embodiment, the liquidcrystal cell of the region A is not driven (i.e. NW), but the liquidcrystal cells of the outer regions B and C are driven with differentvoltages. In another embodiment, the liquid crystal cells of the regionsA and B are not driven (i.e. NW), but the liquid crystal cell of theouter region C is driven. In an alternative embodiment, the region Arefers to a hollow or a transparent plate allowing light directlypassing therethrough, and the regions B and C refer to different liquidcrystal cells as the light-valving structures driven by differentvoltages, so as to individually regulate the ratio of the luminousfluxes of the respective regions.

According to an alternative embodiment, as shown in FIG. 15, the areasof the color-adjusting phosphor layers in the respective regions A, Band C are changeable as needed. In view of the issue of the space colorshift at various regions of the LED light source, the color-adjustingphosphor layers are patterned to regulate the color temperature atdifferent regions. As a result, the issue of the space color shift inthe LED light source can be resolved.

In an alternative embodiment, as shown in FIG. 15, the color-adjustingphosphor layers of the three regions A, B and C are disposed in variousthicknesses. In view of the issue of the space color shift at variousregions of the LED light source, the color temperatures at differentregions are adjusted so as to make the color temperatures being close toeach other or in consistency.

In an alternative embodiment, as shown in FIG. 15, the liquid crystalcells of the three regions of A, B and C are driven by various voltages.Along with the various patterns or thickness of the color-adjustingphosphor layers at the regions A, B and C, the intensity andchromaticity of the hybrid outgoing light emitted from the regions A, Band C are simultaneously adjusted and mixed, so as to resolve the issueof the space color shift in the LED light source.

In an alternative embodiment, as shown in FIG. 15, the liquid crystalcells of the three regions of A, B and C serve as the light-valvingstructure, which can be replaced by the MEMS assembly, the piezoelectricelement, the color changing glass, the electronic paper, theelectrowetting element or the combinations thereof. In anotheralternative embodiment, the color-adjusting structure is thecolor-adjusting phosphor layer in pattern, which may be replaced by dyeor a combination of phosphor and dye.

According to an alternative embodiment, different from the embodiment ofFIG. 10, the color-adjusting phosphor layer is patterned as shown inFIG. 16. The larger area of the region A (85%) is located at peripheryand the smaller area of the region B (15%) is situated at inner area.Along with additional optical elements, the lights of different colorsare more easily to be mixed to achieve uniformity in color temperature.Alternatively, as shown in FIG. 17, a region can be sub-divided intothree regions A, B, and C, and the outer region A has a proportionlarger than the regions B and C. Similarly, the outgoing light can beeven uniformly mixed along with proper optical elements.

As shown in FIG. 18, according to an embodiment of the presentinvention, an interference structure element made of the MEMS assembly,the luminous flux and chromaticity of the outgoing light from theelement is controlled by adjusting the spacing between two thin filmunits 1801, 1802 and 1803 to achieve wavelength conversion of incidentlight 1804 by means of thin film interference. In this regard, theinterference structure element can be configured as both thelight-valving structure and the light-adjusting structure.

FIG. 19 shows an embodiment according to the present invention. Theelectrodes of the region A and region B in FIGS. 19A and 19B areindependent from each other so that the liquid crystal cellscorresponding to the two regions and voltages applied to the two regionsmay be controlled individually. FIG. 19A indicates that both of theyellow phosphor region A occupying 50% of a total area and the uncoatedregion B occupying 50% of the total area are not driven (i.e. NW), inwhich there still is unconverted blue light transmitted out of theregion A. FIG. 19B indicates the light transmittance of driving a blueLED 1926 in the transmission region B. Furthermore, the two regions maybe controlled by individual voltages simultaneously (dual drivingmodes). According to the embodiment, a photoluminescence dye is doped inthe liquid crystal cell 1922, which is selected to radiate wavelength inred light band under blue light excitation. Thus, such redphotoluminescence dye 1924 doped in the liquid crystal cell 1922 makesblue LED light have a additional spectrum of red light wavelength bandafter passing through the liquid crystal cell 1922. The covering extentof the blue LED and yellow phosphor 1930 on the chromaticity diagram maybe expanded by the means of doping the liquid crystal cell with a reddye, i.e. increasing the color rendering of mixed light. As shown inFIG. 12, after the blue light source passes through the liquid crystalcell, the chromaticity coordinate thereof moves from point p to point m(after red dye is doped). The chromaticity coordinate of mixed blue/redlight of the region B is point m, and the chromaticity coordinate ofmixed blue/yellow light of the region A is point q in FIG. 12. The colortemperature of the intersection point of line mq and the BBL is point n.With regard to a line mq, for two end points of different color lights,respectively controlling the intensities of the two color lights (i.e.the transmittance of the region B and region A) may accurately adjustand acquire a color temperature represented by any chromaticitycoordinate on the line mq.

In an alternative embodiment according to the present invention, theliquid crystal cell is doped with aforementioned red dye and yellow dye,which is also located within the liquid crystals, and the yellowphosphor is excited by the blue light and emitting light having theyellow light band, so as to make the blue light passing through theliquid crystal cell have both red and yellow wavelength bands. The lightis then mixed with the cold white light emitted from the yellow phosphorlayer of the region A.

In another alternative embodiment according to the present invention,the liquid crystal cell is doped with nanoparticles of quantum dot (forexample, CdSe, CdS, etc.) having PL effect. The nanoparticles may spreadevenly in the liquid crystal cell, have similar effect as presented bythe doped dye, and is used for pre-adjusting a wavelength band ofoutgoing light passing through the liquid crystal cell. According to oneembodiment, quantum dots may combine with dyes for use and may be dopedin the liquid crystal layer and/or in the phosphor layer.

Doping the liquid crystal cell with quantum dots, dyes and nano-phosphormaterials (or patterning these materials in the form of spacers in theliquid crystal layer or the like) can adjust a wavelength band ofoutgoing light as passing through the liquid crystal cell (i.e. thelight-valving structure). The aforementioned embodiments are referencedembodiments with the color-adjusting structure (wavelength-bandconverting material) in the light-valving structure to form an integralstructure.

FIGS. 20A and 20B show the color regulating device for illumination inaccording to embodiments of the present invention. The device furthercontains a blue LED light source 2002 in operation. The region A iscoated with a yellow phosphor 2003, the region B is uncoated, and theregion C is coated with a red phosphor 2001. When all regions A, B, andC are not driven (FIG. 20A), the blue/yellow mixed light of the regionA, the pure blue light of the region B, and the blue/red mixed light ofthe region C are all in on state (i.e., NW). When operating, the regionsA and B can be not driven (FIG. 20A) and only the region C coated withthe red phosphor 2001 is driven. When the region C reaches an off stateunder the applied voltage (FIG. 20B) in a manner similar to that shownin FIGS. 11A and 11B, the yellow/blue mixed light of the region A refersto the chromaticity coordinate N and the pure blue light of the region Brefers to the chromaticity coordinate B in the CIE chromaticity diagramin FIG. 21. For two end points of different color lights, respectivelycontrolling the intensities of the two color lights (i.e., thetransmittance of the regions B and A) may precisely regulate any colortemperatures represented by the line NB, which intersects the BBL curveat chromaticity coordinate α, as illustrated in FIG. 21.

When the region C is not driven, the mixed light of the red light andblue light outgoing from the region C has a chromaticity coordinate atpoint M in the CIE 1931 chromaticity diagram. By referring to FIG. 21,it is known that individually driving the liquid crystal cellcorresponding to the red phosphor layer of the region C and the liquidcrystal cell corresponding to the phosphor-uncoated region B canregulate the color temperature coordinates of outgoing mixed light tomove along a line αγ in the CIE 1931 chromaticity diagram in FIG. 21. Inother words, color temperature of the mixed light is adjusted along BBLcurve.

Further, the relative areas of the regions A, B and C are schematic, inwhich the three areas of the regions are variable as implementation. Asmentioned above, all permutations and combinations of parameters ofconcentration (c1), thickness (t1), depth (y1), area (a1) of the yellowphosphor layer coated on the region A and concentration (c2), thickness(t2), depth (y2), area (a2) of the red phosphor layer coated on theregion C may be used for more accurately regulating color temperature ofdesired mixed light. For example, in case of the increase in theconcentration c2 of the red phosphor, or in the thickness t2, or changein another suitable area ratio of the A, B and C regions, the originalchromaticity coordinate M can be shifted to M in the chromaticitydiagram (as shown in FIG. 21). At this time, independently driving theliquid crystal cell corresponding to the phosphor-uncoated region B andthe liquid crystal cell corresponding to the red phosphor layer of theregion C can manipulate the movement of the chromaticity coordinates ofoutgoing mixed light along line ac3 in the CIE 1931 chromaticity diagramin FIG. 21.

According to another embodiment of the present invention, in operationif the color temperature of the outgoing light is not necessarily movingalong the BBL curve, but to be fixed at a certain chromaticitycoordinate (e.g., the point γ in FIG. 21) of the BBL curve, onlyrelative intensity of two end points (N, M) of color lights should beregulated. That is, it is only required to regulate the liquid crystalcells corresponding to a single region of yellow phosphor layer (or aregion of red phosphor layer). In addition, under a circumstance ofproperly choosing the parameters like phosphor concentrations,thicknesses and areas of the regions A and C, along with the suitableintensity of blue LED, the uncoated region B in FIG. 20 is optional anda specific chromaticity can be sufficiently achieved by mutuallyregulating the regions A and C.

According to an embodiment of the present invention, the liquid crystallayer structure in FIG. 20 is provided. The present embodiment is onlydifferent from the in embodiment of FIG. 20 in that the yellow and redphosphor materials of the phosphor layer are replaced with yellow/reddyes or yellow/red pigment materials, or the combination of dyes andpigments. In the present embodiment, the aforementioned yellow phosphormaterial, yellow dye or yellow pigment is the first wavelength-bandconverting material, and the red phosphor material, red dye or redpigment is the second wavelength-band converting material. Accordingly,the wavelength-band converting material refers to as a firstwavelength-band converting material and a second wavelength-bandconverting material. The first wavelength-band converting material andthe second wavelength-band converting material may be disposed ordispersed in the liquid crystal layer to form the integral structure, orbe coated on at least a portion of a surface of the transparent plate,or be dispersed inside the transparent plate. The transparent plate mayabut or not abut the liquid crystal layer structure to form the separatestructure.

According to another embodiment, the first wavelength-band convertingmaterial and the second wavelength-band converting material are coatedon the surface of the first or second side of the first light-permeablesubstrate, or are coated on the surface of the first or second side ofthe second light-permeable substrate, so as to form the separatestructure.

The color regulating device and method capable of regulating wavelengthband according to the present invention may simplify and optimize use oflight sources. By accurately fine regulating wavelength band withdifferent light sources (non-coherent visible light, ultraviolet,infrared, and coherent laser light source) or by using “continuouslyextensive adjustment of wavelength band” to replace illumination ofmulti-wave-band light sources, thus employing multiple light sourceswith different wavelengths is not necessary and the cost is greatlylowered. According to an embodiment of the present invention, the colorregulating device for illumination is used to accurately and efficientlycontrol the chromaticity coordinate of the outgoing light within thePlanckian locus of the black body radiation spectrum. Further, theillumination apparatus according to the embodiments of the presentinvention, the illumination products can be made with a fixed colortemperature or a variable color temperature product.

So-called light sources of the present invention generally mean lightsources that are able to emit light with a specific wavelength band ormultiple mixed wavelength bands (including incandescent lamps, CCFL andLED light sources). The light sources can use a chosen PL materialaccording to variation of luminous flux ratio in the CIE 1931chromaticity diagram to achieve a mixed light having a desired specificwavelength band or white light. The present invention explains by LEDlight sources for an example, because the problems of the colortemperature of the LED white light sources itself deviating the naturallight (color shift) and having insufficient color rendering are suitablefor explaining the effects of the color regulating device and colorregulating method for illumination according to the present invention.As mentioned above, if a white LED has color shift, the colortemperature falls out of the grids region extent of FIG. 2, which meansthe white light LED is completely valueless for the indoor illuminationapplication. However, by using the color regulating device and colorregulating method for illumination in according to the presentinvention, the LED light source with color shift can be adjusted to thecorrect color temperature as shown in the BBL locus. Nevertheless,although the embodiments of the present invention use LED light sourcesfor explanation, a person of ordinary skill in the art, after readingthe disclosure of the present invention, will understand that the deviceof the present invention also has the same effects to other lightsources.

In an embodiment according to the present invention, high intensitylight sources through the liquid crystal layer structure are used toadjust luminous flux of light entering phosphor with specific color andthen mixed with light excited by the phosphor to generate “lightmixture” effect. Furthermore, the present invention can use liquidcrystals to adjust the color of light sources from cold colored light towarm colored light all the way without apparently changing the intensity(luminous flux variation less than 15%). For the application of accurateadjustment of color temperature, variation of luminous flux can be muchsmaller to lower than 7%, so that it is difficult for a naked eye to beaware of the change. Furthermore, the present invention also overcomesconventional problems of light flickering during intensity adjustment ofLED using electric current or complicated circuit designs for currentLED chips.

Evenly Mixing of Outgoing Light-Diffusion Film and Light Guide Plate

An element made by the color regulating device for illumination of theexemplary embodiment according to the present invention has a size of1.5 cm×1.5 cm. White light mixed by a distribution region of thephosphor that is formed in a specific pattern probably looks not evenlywhite due to unduly large light spots of blue light or yellow light. Atthis time, using a diffusion film to evenly diffuse colored light canblur a boundary between different colored light to make the wholecolored light well mixed and uniform.

The diffusion film is mounted at a side of the device element of theexemplary embodiment opposite to the light source. To make a light bulb,a diffusion film may be coated on an inside layer of the light bulb. Thediffusion film may also be replaced with a diffusion plate and diffusionlens. For example, using the light guide plate (LGP) makes projectionmodes of light rays more diversified. Large amount of SiO₂ particlesinside the light guide plate (LGP) can make light rays to uniformlyscatter and radiate into all directions, which makes the LGP have thesimilar function as that of diffusion film. Moreover, the diffusion filmcan be added on the LGP to further increase the uniformity of mixedlight in intensity and color temperature. The region without the needfor light transmission is covered by a reflecting mirror so that lightto be transmitted on the region is reflected to another place. In actualapplications, the diffusion film, diffusion plate or diffusion lens islocated an outgoing light side of or surrounding the color regulatingdevice for illumination.

Position of the Light Source of Incident Light Relative to the ColorRegulating Device

According to the embodiment of the present invention, incident lightfrom the light source can also use reflective optical elements to guidethe light of the light source to the light-valving structure (forexample, a reflective liquid crystal layer structure, a color changingglass with a reflective mirror, an electronic paper, a reflectiveelectronic book, a reflective electrowetting element, or a micro electromechanical system device/piezoelectric device with a mirror reflector).After passing through the reflective light-valving, the light of thelight source is reflected, a luminous flux of the reflected lightentering the wavelength-band converting material is controlled and thenthe converted reflected light is mixed with the light of the originallight source without reflection or wavelength conversion to furtheradjust the color temperature of the reflected light. In other words, thelight of the light source can first pass through the color-adjustingstructure before entering the light-valving structure.

In the embodiment according to the present invention, because relativepositions of the color-adjusting structure, light-valving structure andincident light source may be combined to generate functions or may actindividually and then are combined to achieve purposes of regulatingcolor temperature of light, the color-adjusting structure may be locatedin front of the light-valving structure (i.e. the position between thelight-valving structure and light source), located behind thelight-valving structure, or cooperate with other optical elements forany combination of spatial relative positions.

Three Dimensional Structure Formed by Multiple Light-ValvingStructures/Color-Adjusting Structures

In the embodiment according to the present invention, at least twolight-valving structures (such as liquid crystal layer structures, colorchanging glasses) are used and set with a three dimensional framework,respectively control light-valving structures, further independentlyadjust luminous fluxes of outgoing lights entering correspondingcolor-adjusting structures. A cutoff point along BBL curve can beintroduced between the two end points α, β in FIG. 1 to achieve adesired color temperature (for example, the color temperature closer toBBL curve).

In other words, one or multiple light-valving structures and one or morewavelength-band converting elements may be combined to form a threedimensional structure. The three dimensional structure may cooperatewith optical elements (for example, mirror surfaces, lenses, etc.) torespectively or alternatively guide incident light into thelight-valving structures in three dimensional structure according todesign, then adjust required luminous flux of the outgoing lightentering a corresponding wavelength-band converting element so thatcolor temperature of the final outgoing light may be fine adjusted forachieving the purpose of being closer to BBL curve.

Light Path Adjusting Structure

The embodiment of the device, apparatus or method according to thepresent invention may use a prism or special structure to improveoptical effects. To improve the brightness or polarization effects(converting light into a polarized light in the transmittance directionof an optical element), the color regulating device according to thepresent invention may selectively include any appropriate opticalelement such as lens, mirrors, light guide plate, brightness enhancementfilm (BEF), dual brightness enhancement film (DBEF), prism sheet,polarizer, lenticular film and combination thereof.

Referring to FIG. 22 of an embodiment of the present invention, achromaticity coordinate of the used white light is a point ∘: (CCx,CCy)=(0.3, 0.25). The yellow phosphor is used with an outgoing yellowlight at a chromaticity coordinate c in the CIE chromaticity diagram, sothat the outgoing yellow light (chromaticity coordinate c) passingthrough the liquid crystal layer structure as a light-valving structureand a chromaticity coordinate of white light at point ∘ are linked toform a line oc in the CIE chromaticity diagram. The line oc passesthrough and intersects BBL at a point β, which is a chromaticitycoordinate of warm light.

In an alternative embodiment, the yellow phosphor is replaced by anorange-yellow phosphor to obtain a mixed warm light with an even warmercolor temperature than that of the original mixed light. Oppositely, ifa mixed light with a colder color temperature is desired, the yellowphosphor then is replaced by an green-yellow phosphor, such that themixed light of outgoing light from the green-yellow phosphor and theoriginal white light will become a cold white light or cold light.

At present, an LED white light source inevitably has a spectrum that theblue green part is stronger, the yellow green part is weaker, and thusthe yellow green part of the spectrum is sunken. Furthermore, when onlyyellow light is mixed with blue light, color temperature thereof tendsto be cold and makes people feel uncomfortable. At this time, a red dyeor red phosphor material may be added for color adjustment to make bluelight become purplish light. The purplish light is then mixed withyellow light to obtain mixed light with warm color temperature.

Accordingly, the exemplary embodiments of the color regulating device ofthe present invention may be used to accurately adjust the unnaturalwhite light deviating from BBL and identified by human eyes to BBL curveor to any other desired chromaticity coordinate.

In an alternative embodiment of the present invention, the blue lightsource is partially replaced with a white light source.

According to an alternative embodiment of the present invention, FIG. 23shows a color regulating device for illumination 2300 comprising a layerof color changing glass 2302 serving as a light-valving structure. Thecolor changing glass is not light-permeable when no voltage is appliedand gradually becomes light-permeable when applied voltage increases dueto reduction-oxidation (redox) reaction of contained materials therein.The color changing glass 2302 is divided into three parts of regions A,B, and C. According to the embodiment, the region A is a transparentplate not contained the redox material and ITO electrodes therein.Surfaces of two of the regions (i.e. regions B and C) are respectivelycoated with ITO electrodes that are independent from each other. A blueLED of 450 nm wavelength serves as the backlight source. A surface ofthe region A is coated with a yellow phosphor layer, a surface of theregion B is coated with a light-yellow phosphor layer and a surface ofthe region C is coated with a red phosphor layer. As shown in FIG. 24,the outgoing lights form the respective three regions represent pointsA, B and C in the chromaticity diagram of CIE 1931. Through the voltagecontrol of independent ITO electrodes in B and C regions, grayscales ofthe regions B and C in the color changing glass 2302 are respectivelyadjusted by variation of the voltages between ITO electrodes in thesetwo regions, so as to control the ratio of the luminous fluxes of thelight-yellow/blue light transmitted through the region B and thered/blue light transmitted through the region C, to achieve purposes ofaccurately regulating color temperature.

Referring to FIG. 24, to precisely control the color temperature of ahybrid light, the respective A, B and C regions need an optimizeddistribution in area. Afterwards, a light-yellow phosphor layer and ared phosphor layer respectively corresponding to the region B and regionC are independently driven to control their luminous fluxes, such thatthe color temperature of an outgoing hybrid light can be regulated alongthe line αγ in the chromaticity diagram of CIE 1931. In other words, thecolor temperature can be regulated along the BBL.

When light rays of three different color temperatures emitted from theregions A, B and C are mixed, the hybrid light can be any point of thechromaticity coordinate within a triangular region enclosed by thechromaticity coordinates A, B, and C.

According to alternative embodiments of the present invention, as shownin FIG. 23, a color changing glass 2302 in three A, B, and C regions, oronly in two B and C in regions (A regions without filling redoxmaterials or coating ITO electrodes) serves as the light-valvingstructure, which can be replaced by the MEMS assembly, the liquidcrystal layer structure, the electronic paper, the electrowettingelement or the combinations thereof.

According to an embodiment of the present invention, the transparentplate in FIG. 15 can be replaced by a color changing glass. Thetransparent plate may be replaced with the color changing glass tobecome an additional means for adjusting a luminous flux ratio ofincident light and outgoing light.

Illumination Apparatus

As shown in FIG. 25A, according to an exemplary embodiment of thepresent invention, a color regulating apparatus 2510 for illuminationhas a color regulating device 2511 which comprises a liquid crystallayer structure 2512 and a phosphor layer 2514. The color regulatingapparatus 2510 also comprises LED light sources 2516 mounted in a casing2518. The inner surfaces of the casing 2518 are coated with mirrorsurface coating 2519 to reflect leftward, rightward and downward lightrays of the LED light sources to the color regulating device 2511.

FIG. 25B shows another alternative embodiment of the present invention.A color regulating apparatus 2520 for illumination has a LED lightsource 2526, a color regulating device 2521 and a casing 2528. The colorregulating device 2526 includes a liquid crystal layer structure 2522and a phosphor layer 2524. The LED light sources 2526 in the colorregulating apparatus 2520 do not abut the liquid crystal layer structure2522 in the color regulating device 2521 but is at a distance d from thecolor regulating device. Because the distance from the LED light sources2526 of the current alternative embodiment is larger than that in thecolor regulating apparatus 2510 in the above embodiment shown in FIG.25A, under the same light source condition, an environmental temperatureT_(B) in which the liquid crystal layer structure 2522 is placed islower than the color temperature T_(A) in which the liquid crystal layerstructure 2512 is placed. Furthermore, the casing 2528 of the currentembodiment is not coated with a mirror surface coating.

Additionally, with the concept of a light guide plate (LGP), it ispossible to design any LGP shapes. For example, a column shape LGPallows light rays entering the light guide “column” to diffuse andscatter in the column and make the whole light guide column evenly“shine”.

In a color regulating apparatus for illumination according to anexemplary embodiment of the present invention, FIG. 26A shows asemispherical light bulb 2610, which has a base 2618, a casing 2617 anda diffusion film layer 2611 coated evenly on an inner layer of the lightbulb 2610. As shown in the figure, SiO₂ particles 2613 with differentsizes are spread inside a rod-shaped LGP 2612, which can expand andspread the mixed light to the whole semispherical light bulb by thecolor regulating apparatus 2610 for illumination of the exemplaryembodiment according to the present invention. The LED light sources2615 in the current embodiment not only separate from the liquid crystallayer structure 2616 but also have transparent adiabatic material 2614disposed between the LED light sources 2615 and the liquid crystal layerstructure 2616 to further lower the environment temperature in whichliquid crystal layer structure of the apparatus is placed.

FIG. 26B shows a color regulating apparatus for illumination accordingto an exemplary embodiment of the present invention, a column-shapedlight tube 2620 includes a color regulating apparatus 2630 forillumination similar to that in the embodiment shown in FIG. 25A. Thecolor regulating apparatus 2630 comprises LED light sources 2625, acasing 2627 and color regulating devices for illumination-color changingglasses 2626. As shown in FIG. 26B, the LGP 2622 is column-shaped andallows mixed outgoing light to evenly emit from the whole column.Therefore, the column-shaped LGP 2622 may be designed to serve as a“light tube.” With the diversified LGP designs, the color regulatingapparatus for illumination may be applied more widely in variousaspects.

In the aspect of adjusting light intensity, conventional incandescenttungsten lamps or cup light commonly used in hotels may use a simplelight adjuster (fixed voltage and adjust the electric current bychanging resistance) to accurately continuously adjust the intensity ofthe light source. The LED itself is a diode that the characteristiccurve of current versus voltage is an exponential function so thatconventional adjusters cannot be used for controlling and changing lightintensity at will. Most of currently marketable LED light bulbs adjustlight intensity by stages, for example, 8-stage variable intensity. Suchmanner needs an additional complex controlling module to replace thesimple light adjuster so as to greatly increase the cost. An LED lightbulb with continuous adjustment functions, when set in low lightintensity, has unstable flickers, which decreases the lifespan of suchLED light bulb and hurt human sense.

A light bulb switch may be integrated with a variable resistor knob (byusing a latch-type knob), such that the voltage across a liquid crystalelement, i.e. the light-valving structure, can be changed via adjustingthe resistance of the variable resistor, so as to manipulate theluminous flux of the light through the liquid crystal element. As aresult, the color temperature of the hybrid light through the deviceaccording to the embodiments of the present invention can becontinuously changed, or only be changed in intensity of the outgoinglight. In an alternative embodiment according to the present invention,a base of the light bulb 2610 is mounted with a “circular knob” toadjust the resistance of the variable resistor, so as to continuouslychange the color temperature of the hybrid light, or only change theintensity of the outgoing light.

According to an embodiment of the present invention, a switch or otherfunctions in the bulb can be configured as a controlling circuit, whichcontrols the voltage to manipulate the luminous flux of the lightthrough the light-valving structure or the color-adjusting structure, soas to continuously change the color temperature of the hybrid light oronly to change the intensity of the outgoing light.

In another alternative embodiment according to the present invention,the color regulating device achieves wavelength conversion of incidentlight by an interfering means (by adjusting the space between the twoaforementioned thin sheet-like materials) instead of using awavelength-band converting material.

In another alternative embodiment according to the present invention,LED light sources and the color regulating device according to thepresent invention are mounted two ends of light guide plate (i.e. columnor tube) with an appearance similar to a current fluorescent lamp tubeand to replace the fluorescent lamp tube which uses electricity toexcite mercury vapor for stimulating the phosphor. The light guide plate(LGP) often has submicron particles dispersed in it to make the lightrays scatter evenly. Moreover, the diffusion film can be furtherattached on the LGP to make the light scattering more uniformly in it.With regard to the embodiment of long light tubes, besides two ends of alight guide tube, multiple LED light sources and corresponding colorregulating devices can be mounted in intermediate parts of the lightguide tube.

It is worth to mention that backlight sources (for example, LEDs, CCFLs)cooperates with liquid crystal layers for adjusting grayscale to controllight fluxes of the three primary colors of a pixel entering a filter sothat the desired color for the pixel is obtained. Such structure hasbeen commonly used in liquid crystal displays (LCDs). However, so-called“display” means that the display relies on pixels of N×M to make humaneyes to obtain recognizable information and presents specific pictures(i.e. motion pictures) during persistence of vision. In other words,recognizable or realizable information (or pictures) must be givenpeople. Therefore, displays all need complicated driving circuits. Adriving circuit needs to completely scan all pixels of the display basedon required signals of three primary colors within a period of 16 ms.Both N and M values are at least large from 100 to 200 to enable afunction of the display; otherwise a problem with insufficientresolution (insufficient information expression) happens.

On the contrary, it is different to use patterned color-adjustingstructure to cooperate with liquid crystal cells for illumination. Itneeds neither hundreds of pixels nor complicated driving circuits andhas no problems requiring fast response time of liquid crystals.Furthermore, the greatest difference between liquid crystal cells andLCDs is that the liquid crystal cells are not required to sendhuman-recognizable pictures or information. Moreover, LCs used indisplays, due to the requirement of high-quality motion pictures, needto have properties such as fast response time, high contrast ratio, wideview angle, etc. Therefore, stability of LC materials for displays ishighly required. On the other hand, the LC alignment layer may be madeby an inorganic deposition method, which results in an inorganicalignment layer with the advantages of better heat resistance than thetraditional alignment layer, so as to be more suitable in theapplication of indoor illumination. Also, using high-energy ion beambombardment on a target surface is an alternative way of producing LCalignment.

In summary, because purposes of the liquid crystal layers for LC cellsand LCDs are totally different, numbers of the liquid crystal cellsdriven by voltage to adjust grayscale are greatly different. Specificconditions must be required for a display so that it is impossible touse few liquid crystal cells serving as light valves for a display.Different from the LCs used for displays, the LC layer structure of thecolor regulating device according to the present invention is requiredto consider light transmission efficiency and bearable temperature ofheat generated by light sources. Also, liquid crystal cells withnormally white mode and normally black mode may be used to continuouslyadjust the outgoing light of any light sources (such as LEDs) frombrightness to dark or from dark to brightness without flickeringhappens. What is more important is that a conventional LCD filtercompletely converts light of a backlight source to three primary colorsof red, blue and green or four colors and totally absorbs light of otherwavelength bands in sub-pixels. Therefore, after the light from thebacklight source passing through the LCD filter of the three primarycolors, each of the sub-pixels normally has luminous flux loss over 70%.If taking the polarizer into consideration which absorbs at least morethan 50% of the backlight source, the intensity of outgoing lightrelative to that of the backlight source is less than 15%. Moreover,with the absorption of other additional optical films, the lighttransmission becomes much lower than 15%. On the contrary, the colorregulating device and method according to the present invention convertpart of light of the original light source through the wavelength-bandconverting material (e.g. phosphor) and then the converted light ismixed with other part of the light (e.g., the light passes through theLC cell) of the original light source. As illustrated above, if thepolarizers occupy less than 25% of the total area of all LC elements,the luminous flux loss is lower than 15%. Therefore, if using thenon-absorption polarizer to replace the aforementioned traditionalpolarizer, the loss of luminous flux can be further reduced to be lowerthan about 7%. Further, in the application of the present invention toaccurately regulate the color temperature of a light source, since thearea of the LC elements to be driven can be even smaller, the luminousflux loss can be reduced to a level below 7%. If using the colorchanging glass as the light valve without need of the polarizer, theluminous flux loss can be even reduced down to about 3-5%, which means alight transmittance higher than 95%. Given the above, in that any lightsources can be adjusted to achieve color temperature of “sunlight” bymore economical manners, human lifestyle is greatly changed.

Because light wave itself has electromagnetic characteristics and maytransfer freely between other types of energy (for example, heat,potential energy), once accurately controlling the wavelength band isachieved by the embodiments of the present invention, it can be appliedextensively to various fields of human life. For example, the accuratecolor regulating device and apparatus according to the present inventionmay be applied to various fields. Besides the purposes of indoors andoutdoors illumination (table lamp, desk lights, etc.) the device andapparatus may be also used extensively in fields of outdoors buildinglight projection and advertisement illumination, traffic light devices,car lamps, medical treatment purposes (beauty laser,anti-bacteria/anti-virus/anti-fungus purposes againstbacteria/virus/fungus propagation and cultivation, anticancer purpose,radiation and decomposition of specific allergens, etc.), human factorapplication (mood and art lighting, reinvigoration, sleep assistance,vision assistance, etc.), energy (batteries, etc.), signal transmission(optical fibers, continuous modulation coupling elements, frequencydividers for dividing light waves with different frequencies, etc.),safety facilities and installations (escape apparatuses, etc.),inspection and analysis (non-destructive material inspection,spectrometers, etc.), optical elements (microdisplay light sources,optical pickup heads, etc.), agricultural applications and ecologicalcultivation (planting, fruit nurture/greenhouse breeding and fisherycultivation and catching of fishes/shrimps/crabs/shellfishes, etc.),military purposes (night vision/head up display, etc.), aviation (alarmand illumination, etc.), and wilderness survival.

The color regulating device, apparatus and method according to theembodiment of the present invention, in the medical field, may providelaser light sources with different wavelength bands forremoving/weakening dark spots (elder spots, age spots, pigment spots,liver spots, dark regions and angiomas), laser removing moles and hairs,grinding cuticle, tightening skin by electric wave, and reducing poresof the skin. The popular laser cocktail therapy recently combines laserdevices emitting laser beams with different wavelengths and power (forexample, depi-light laser, intense pulsed lasers with different colors,white intense pulsed light, ruby laser and pulsed dye laser, etc.) toachieve effects of removing/weakening spots, laser removing moles andhairs, grinding cuticle, tightening skin by electric wave, and reducingpores of the skin. Finally, skin with white color and tightness as wellas a ceramic doll can be acquired.

Furthermore, an embodiment according to the present invention may beused in photodynamic therapy purposes. The photodynamic therapy wasoriginally developed for restraining proliferation of malignantmelanoma. After greatly lowering its power, the photodynamic therapy iswidely used in beauty medical fields. So-called photodynamic lightincludes two different light sources having red light with wavelengthsof 633 nm and blue light with wavelength of 413 nm. In the visiblespectrum, the red light with the longest wavelength penetrates deepestso that photodynamic red light is capable of entering the dermal layer,expanding, strengthening blood capillary to improve blood circulation,stimulating fibroblast cells, strengthening collagen fiber structures toachieve purposes of weakening fine wrinkles. The photodynamic red lightmay also be used in therapies of super dry or atopic skin. For example,after skin is smeared with skin care products having high moisturizingperformance and vitamin C, red light is applied on the skin to activatecells of outer skin and achieve curing and moisturizing purposes.Photodynamic blue light is mainly used to cure acnes that are commonlyreferred to pimples. Acnes result from that the proliferation ofpropionibacterium acne which is capable of decomposing sebum and causesfolliculitis of the sebaceous glands. Such acnes generate phosphor iscalled “porphyrin.” However, irradiation of blue light of specificwavelength changes the characteristic of such porphyrin to killpropionibacterium acne and achieve purposes for curing acnes.

According to researches, irradiation of light wave with a specificwavelength or color temperature helps to accelerate thedifferentiation/duplication/proliferation of stem cells, assist cellsand tissues culture, and improve biomedical and physiological relatedresearches. The embodiment according to the present invention focusesthe adjusted and mixed light to irradiate parts of cells suchirradiation on scalp to activate/regenerate cells for activating hairfollicular cells or improving blood circulation around hair follicles toachieve purposes of hair restoration/hair thickening and loweringseborrheic dermatitis.

The embodiment according to the present invention may be used insurgeries and therapies of eye related diseases. For example,continuously leading light with different wavelength bands into an eyelens to scatter collective floaters of myodesopsia or leading the lightinto the lens to scatter turbid matter incurring cataract or make theturbid matter absorb the light with the specific wavelength and thendecompose. Glaucoma arises because increased intraocular pressure causedby worse liquidity of aqueous humor of the anterior chamber of eyespresses optic nerves. Therefore, irradiation light with a specificwavelength band is used to make aqueous humor of the anterior chamber ofeyes to flow normally and then reduce the intraocular pressure.

The embodiment according to the present invention may be used in opticalinstruments such as laser light sources of (optical) telescopes and(optical) microscopes to stimulate fluorescent protein, assistant lightsources for photography/inspection/therapy/surgery of endoscope orlaparoscopes with changeable wavelength band, skin cancer inspectionsuch as irradiation on “sections” of specimen taken from cancer stagingsurgery with a specific light source and analysis of color of the tissuesections, and urine (protein) spectrum inspection. In the embodimentaccording to the present invention, the light source with accuratelycontrolled wavelength band or color temperature may be used in criminalidentification. Under irradiation with a multi-wave-band light source,different human tissues (for example, bloodstains) and artificialproducts (for example, fibers) show specific colors.

In the embodiment according to the present invention, the light capableof continuously regulating color temperature or wavelength band may beused in cell culture/physiological experiment and researches of organsand tissues (for example, optical fibers are led into a brain to forirradiation/collection/analysis of reaction). Furthermore, it may beapplied to experimental and research fields of chemistry/physics/(Ramanor FTIR spectrometers)/material (interferometers for measuring materialthickness, 3D topology surface analyzers)/chemicalengineering/electro-optical/biological (HPLC)/test tube for lightscattering (experimental understanding the process of dynamic behaviorfrom molecular reaction).

A laser beam with a specific wavelength band can stimulate fluorescentprotein, amino acid, and tissues that are dyed by fluorescent dyes. Dyesare used to mark out tumor regions at the present. For example, blue andgreen lights are used to irradiate organ cells dyed by fluorescent dyes.An embodiment according to the present invention, converts a wavelengthof a single laser light source to employ the light with a changeablewavelength band to irradiate a region to be inspected inside humantissues. With respect to normal and abnormal cells, after it is dyed bymultiple fluorescent dyes with different wavelength reactions, a laserlight source according to the present invention that is fine adjustableand capable of accurately selecting wavelength band is used so that theboundary between normal cells and cancer cells may be delimitedexplicitly even the cancer cells are a few. Thus, the cancer or abnormalcells may be excised in a staging surgery as far as possible. Forexample, if a specific cancer cell corresponds only to a specificfluorescent dye (for example, yellow green light with a specificwavelength band is the most reactive), adjusting the laser light sourceto specific intensity ratio of yellow and green light in a surgery willfind out the position and deal with the abnormal cell tissues of thespecific cancer cells.

The embodiment according to the present invention may be used in lightsources for photo curing dental curable materials.

There are researches indicating that specific wavelengths or wavelengthbands accelerate or affect the growth of animals/plants. The embodimentaccording to the present invention may adjust and change the colortemperature or wavelength band of light used to irradiate plants/animalsin a specific environment (for example, a green house or fishpond) basedon time to create illumination conditions most advantaging the growth ofplants/animals. The embodiment according to the present inventionirradiates with light of the specific wavelength band during operationof fishery cultivation or catching of fishes to accelerate the growth offishes or concentrate the fishes to facilitate catching.

In the embodiment according to the present invention, thewavelength-band adjusting element or method and steps, a specificwavelength-band absorbing material or element may be added into a coloradjusting structure to reduce a luminous flux thereof to adjust colortemperature or wavelength band of the mixed light. For example, aspecific wavelength absorbing material that decomposes and decays astime goes by may be added into objects or food packaging materials andcooperates with a design of mixed light to change the color of the mixedlight through the light color adjusting structure as time goes by sothat the objects or food packaging materials may serve as an indicatoror be designed as a self-timer including an LED light source to indicatethat such object or food has expired.

The embodiment according to the present invention may be used inmilitary purposes, for example, infrared night vision goggles andnear-eye goggles may achieve purposes of enhancement of visual image byfiltering certain wavelength bands of light for information processing.Furthermore, the embodiment according to the present invention may beused in security check of airports (public places); for example,infrared light wavelength band is used to irradiate entering passengersto measure body temperatures for public health. Concerning otherexamples, both large-scale space telescopes and small-scale amateurtelescopes can use stars as light sources to continuously switch aspectrum by the color regulating device of the embodiment of the presentinvention so that the intensity of a spectrum region to be observed ischanged or a wavelength band of the spectrum is converted, for example,the infrared spectrum is converted into other spectrums.

The embodiment according to the present invention uses carbon nanotubesas light-valving structures or directional quantum dots based onphysical, chemical and dynamic characteristics of the carbon nanotubes.For other nanotubes of different materials may also be used as lightvalve. A light source may also use nanotube LEDs (e.g. carbon nanotubesradiates when electrified). Furthermore, the embodiment can cooperatewith carbon nanotubes to connect to specific ingredients for heatdissipation purposes.

The embodiment according to the present invention may use the colorregulating device and method for illumination to generate artificialsunlight; in other words, sunlight simulation devices are accordinglymanufactured for sunlight energy experiments, sunlight lamps or sun beds(or sunbathing machines). In the application of sunlight lamps,regulating the wavelength band of light that the skin pigmentation issensitive achieves purposes of sun tanning skin and also removes thewavelength band that is hazardous to the skin and lowers danger ofcausing skin cancer. The embodiment according to the present inventionmay manufacture low-priced experimental solar simulators. A principle ofthe present solar simulators is to use high-energy plasma excitationwith a plurality of correctors to acquire full spectrum light (the fullspectrum includes a time-varying visible spectrum and low intensive UVand IR frequency spectrums). Generally speaking, sunlight is close toyellow green. The embodiment according to the present invention may usea combination of halogen lamps and incandescent lamps or use LED whitelight sources, IR light sources and UV light sources and cooperate witha light color adjusting structure including yellow green phosphor layerand reducing intensity of blue light to acquire realistic sunlight.

In the embodiment according to the present invention, a light sourcethrough wavelength adjustment may also be used in light and soundentertaining objects such as toys or amusement devices. Moreover, injewelry identification, the device capable of continuously accuratelyregulating color temperature (wavelength band of light) according to thepresent invention is able to provide desired necessary specific lightsources.

The embodiment according to the present invention employs the devicecapable regulating color temperature (wavelength band of light) tochemical/photosynthesis reaction mechanism. For example, in themanufacturing and product synthesizing processes of chemicalengineering/industrial/plastic materials, cracking and synthesizingprocesses of petroleum raw materials, and synthesizing processes ofmedicine, irradiating light of specific wavelength bands duringreactions can accelerate/improve chemical reactions. Furthermore,another embodiment according to the present invention may be used inchemical/industrial fields, for example, in the aspect of breadmanufacturing/wine making processes, yeast is irradiated by a specificwavelength band to accelerate or affect and control activity of theyeast and the progress of yeast reaction.

According to embodiment of the present invention, in exposure machinesof semiconductor photolithography processes using photoresist (forexample, deep UV light sources are used for immersion exposure), usingthe illumination (light irradiation) apparatus of the present inventionmay continuously adjust the wavelength band of light to save lightenergy and lower the cost. Furthermore, multiplicity of variablewavelength band of the light source advances researches in variety ofpotential photoresists and the development of exposure/developingtechnologies.

Although the present invention combines several exemplary embodimentsfor explanation and description, a person of ordinary skill in the artmay understand that changes or modifications can be made withoutdeparting from the scope and spirit defined in the attached claims ofthe present invention. For example, the light valve for continuouslyadjusting luminous flux of outgoing light may be changed and replaced bycurrent similar technologies. Alternatively, the CIE 1931 chromaticitydiagram may be replaced by other CIE chromaticity diagram for referenceof BBL coordinate depending on the demands.

What is claimed is:
 1. A color regulating device for illumination,configured to regulate a color temperature of light interacting with thedevice, comprising: a light-valving structure for adjusting a firstoutgoing light of the light from a fully bright state to a fully darkstate, so as to adjust a flux ratio of a first incident light to thefirst outgoing light of the light interacted with the light-valvingstructure, the light-valving structure being a member selected from thegroup consisting of a micro electro mechanical assembly, a colorchanging glass, an electronic paper, an electrowetting element andcombination thereof; and a color-adjusting structure having at least onewavelength-band converting element, configured to convert a secondincident light with a first wavelength band into a second outgoing lightwith a second wavelength band, wherein the light-valving structure andthe color-adjusting structure at least partially overlap on a travelingpath of the light, forming at least one overlapping structure, such thatat least a portion of the light becomes a third outgoing light throughthe overlapping structure, and the first outgoing light, the secondoutgoing light and the third outgoing light are mixed to form a hybridlight with a color temperature different from that of the light.
 2. Thecolor regulating device for illumination as claimed in claim 1, whereinthe second wavelength band covers the first wavelength band.
 3. Thecolor regulating device for illumination as claimed in claim 1, whereinthe overlapping structure is configured as, in view of the travelingpath of the light, the light-valving structure in front of thecolor-adjusting structure or the light-valving structure behind thecolor-adjusting structure.
 4. The color regulating device forillumination as claimed in claim 3, wherein the light-valving structureis a plane light-valving structure or a three-dimensional light-valvingstructure comprising a plurality of the members.
 5. The color regulatingdevice for illumination as claimed in claim 4, further comprising atleast one transparent plate abutting or non-abutting a surface of afirst side of a first light-permeable substrate.
 6. The color regulatingdevice for illumination as claimed in claim 1, wherein thewavelength-band converting element is a wavelength-band convertingmaterial, or a wavelength-band converting structure unit.
 7. The colorregulating device for illumination as claimed in claim 6, wherein thewavelength-band converting material is a first wavelength-bandconverting material, or a first wavelength-band converting material anda second wavelength-band converting material.
 8. The color regulatingdevice for illumination as claimed in claim 7, wherein the firstwavelength-band converting material or the second wavelength-bandconverting material is selected from the group consisting of a phosphor,a dye and combination thereof.
 9. The color regulating device forillumination as claimed in claim 8, wherein the phosphor is selectedfrom the group of an oxide phosphor, an oxynitride phosphor, a nitridephosphor, a zinciferous compound phosphor, a semiconductor phosphor, anorganic phosphor, a photoluminescence dye and combination thereof. 10.The color regulating device for illumination as claimed in claim 8,wherein the dye is an absorption type dye, a photoluminescence type dyeand combination thereof.
 11. The color regulating device forillumination as claimed in claim 6, wherein the wavelength-bandconverting material, coated on a surface of a first side or second sideof a first light-permeable substrate or coated on a surface of the firstside or second side of a second light-permeable substrate, forms aseparate structure.
 12. The color regulating device for illumination asclaimed in claim 1, wherein the hybrid light has a color temperature ina black body locus in a CIE 1931 chromaticity diagram.
 13. The colorregulating device for illumination as claimed in claim 1, wherein thehybrid light is further mixed with at least one of other light.
 14. Thecolor regulating device for illumination as claimed in claim 1, furthercomprising an optical diffusing member selected from the groupconsisting of a diffusion film, a diffusion plate, a diffusion lens andthe combination thereof.
 15. The color regulating device forillumination as claimed in claim 1, wherein the light is selected from agroup consisting of a light emitting diode (LED), an incandescent lamp,a halogen lamp, sunlight, a cold-cathode fluorescent lamp (CCFL),fluorescent lamp and combination thereof.
 16. A color regulating method,comprising the steps of: providing a first light source for emitting afirst light; providing a light-valving structure and adjusting a firstoutgoing light of the light from a fully bright state to a fully darkstate, so as to adjust a flux ratio of a first incident light to thefirst outgoing light of the first light interacted with thelight-valving structure, the light-valving structure being a memberselected from the group consisting of a micro electro mechanicalassembly, a color changing glass, an electronic paper, an electrowettingelement and combination thereof; providing a color-adjusting structurehaving at least one wavelength-band converting element and converting asecond incident light with a first wavelength band into a secondoutgoing light with a second wavelength band, wherein the light-valvingstructure and the color-adjusting structure at least partially overlapon a traveling path of the first light, forming at least one overlappingstructure through the overlapping structure, such that at least aportion of the first light becomes a third outgoing light; and mixingthe first outgoing light, the second outgoing light and the thirdoutgoing light to form a hybrid light with a color temperature differentfrom that of the first light.
 17. The color regulating method as claimedin claim 16, wherein the hybrid light is further mixed with a portion ofthe first light not interacted with the light-valving structure orcolor-adjusting structure.
 18. The color regulating method as claimed inclaim 16, wherein the first light is emitted from a first light sourceselected from a group consisting of a light emitting diode (LED), anincandescent lamp, a halogen lamp, sunlight, a cold-cathode fluorescentlamp (CCFL), fluorescent lamp and combination thereof.
 19. The colorregulating method as claimed in claim 16, further comprising the step ofproviding a second light emitted from a second light source to be mixedwith the hybrid light.
 20. The color regulating method as claimed inclaim 16, wherein the wavelength-band converting element is awavelength-band converting material, or a wavelength-band convertingstructure unit.
 21. The color regulating method as claimed in claim 20,wherein the wavelength-band converting material is selected from thegroup consisting of a phosphor, a dye and combination thereof.